JUDGMENT judgment of court was delivered by Sunil Kumar Sinha, Actg. C. J.-A short question involved in this writ petition is: "Whether, after extension of Income-tax Act, 1961, to State of Sikkim with effect from April 1, 1990, Sikkim State Income-tax Manual, 1948, stands repealed and assessments made thereunder for accounting years 1996-97 to 2004-05 (assessment years 1997-98 to 2005-06) would be without authority of law?" facts, briefly stated, are as under: 2.1 By Constitution (Thirty-sixth Amendment) Act, 1975, Sikkim was admitted as State of Union of India with effect from April 26, 1975, and article 371F of Constitution of India was inserted to provide for special provisions with respect to State of Sikkim. Sub-clause (n) of article 371F empowers President of India to issue public notification and to extend with such restrictions or modifications as he thinks fit to State of Sikkim any enactment which is in force in State in India at date of such notification. On November 7, 1988, Notification No. S. O. 1028(E) (see [1989] 176 ITR (St.) 222) was issued by President of India extending provisions of Income-tax Act, 1961, to State of Sikkim. By further Notification being No. S. O. 148(E), dated February 23, 1989 (see [1989] 176 ITR (St.) 223), Ministry of Finance, Central Government, appointed 1st day of April, 1989, as date on which Income-tax Act, 1961, shall come into force in State of Sikkim in relation to previous year relevant to assessment year commencing on 1st day of April, 1989. By virtue of section 26 of Finance Act, 1989 (see [1989] 177 ITR (St.) 167, 182), Income-tax Act, 1961, was made applicable to State of Sikkim from previous year relevant to assessment year commencing from April 1, 1990, thereby extending date of applicability of Income-tax Act, 1961, by one year from date as specified in earlier notification dated February 23, 1989. 2.2 petitioner-university was established in year 1995 by enactment of State Government, namely, Sikkim Manipal University of Health Medical and Technological Sciences Act, 1995, and it started imparting various courses by constituting its unit. petitioner-university was included in list of universities maintained by University Grants Commission (UGC) under section 2(f) of University Grants Commission Act, 1966, on December 9, 1998. 2.3 On July 7, 2006, Joint Secretary/ITO, Income and Commercial Tax Division, passed assessment order under clause 4 sub-clause (i) of Sikkim State Income-tax Manual, 1948, against petitioner for assessment years 1997-98 to 2005-06 pertaining to accounting years 1996-97 to 2004-05 and income-tax of petitioner was assessed. said assessment order was served upon petitioner with demand notice No. 293/IT for amount of Rs. 7,65,35,648 and petitioner was asked to pay said amount. According to petitioner, sum of Rs. 76,53,655 being 10 per cent. of said amount was deposited by it and appeal was filed by petitioner before Special Commissionercum-Secretary, Income and Commercial Tax Division, Finance, Revenue and Expenditure Department, Government of Sikkim, for cancellation of assessment order dated July 7, 2006, and refund of ad hoc payment of Rs. 76,53,655 with interest. petitioner also claimed exemption under section 17 of Sikkim State Income-tax Manual, 1948. 2.4 On March 3, 2011, appeal of petitioner was dismissed by said authority on two grounds, i.e., (i) special secretary does not have authority to act as appellate authority under Sikkim State Income-tax Manual, 1948, and (ii) petitioner could not produce any document to substantiate that it was charitable institution for claiming income-tax exemption and for non-payment of 50 per cent. income-tax assessed. 2.5 petitioner then agitated matter before Chief Minister of Sikkim, praying for exemption from paying income-tax under Sikkim State Income-tax Manual, 1948, because, according to it, same was already repealed, and refund of ad hoc payment made. 2.6 On September 11, 2012, Additional Commissioner, Commercial Tax Division, Revenue and Expenditure Department, Government of Sikkim, issued memo, based on opinion of Law Department and Law Commission of Sikkim, that repeal of enactment does not extinguish liabilities accrued under repealed enactment and demand having been raised in July, 2006. petitioner was liable to pay income-tax to tune of Rs. 9,09,10,818 under Sikkim State Incometax Manual, 1948, and Department was entitled to realise same by following recovery procedure. 2.7 petitioner, thereafter, made various representations, inter alia, on grounds that Sikkim State Income-tax Manual, 1948, having been repealed, was not applicable upon petitioner and respondent authorities were not entitled to assess and demand income-tax from petitioner from April 1, 1990, when Income-tax Act, 1961, became applicable to State of Sikkim. However, when no relief was granted on those representations, instant writ petition was filed. Mr. S. Pal, learned senior counsel appearing on behalf of petitioner, has argued that Sikkim State Income-tax Manual, 1948, was repealed after extension of Income-tax Act, 1961, to State of Sikkim with effect from April 1, 1990. petitioner is governed by Income-tax Act, 1961, and has now been assessed thereunder. Therefore, any income-tax imposed or levied under Sikkim State Income-tax Manual, 1948, and proceedings for levying such tax drawn by State authorities, vide assessment order dated July 7, 2006, were without jurisdiction and nullity. In terms of article 265 of Constitution of India, no tax can be levied or collected except by authority of law. Therefore, impugned assessment order dated July 7, 2006 (annexure P6), along with other subsequent orders/demands may be quashed and sum of Rs. 76,53,655 may be refunded to petitioner. On other hand, Mr. J. B. Pradhan, learned Additional Advocate General, appearing on behalf of State, has opposed these arguments. He has argued that earlier, when petitioner was assessed under Income-tax Act, 1961, it filed W. P. (C.) No. 13 of 2006 challenging above proceedings by taking grounds that said enactment of 1961 was not applicable to it and petitioner was governed by Sikkim State Income-tax Manual, 1948, and said proceedings may be quashed. Therefore, now, petitioner is estopped from taking different plea and its petition should be dismissed. Mr. A. Moulik, learned senior counsel appearing on behalf of Union of India, has argued that petitioner was liable to pay income-tax under Income-tax Act, 1961. Therefore, after filing earlier writ petition, petitioner succumbed to jurisdiction of competent authority under said Act and after passing orders of income-tax authorities under Income-tax Act, 1961, petitioner has filed appeal so far as assessment years 1998-99 to 2002-03 is concerned. As far as assessment year 2004-05 is concerned, Income-tax Appellate Tribunal "A" Bench, Kolkata, has passed order in favour of petitioner against which appeal under section 260A of Act has been filed before Calcutta High Court, Kolkata, and, thus, matters, relating to payment for income-tax by petitioner under Income-tax Act, 1961, are pending before appropriate forums. We have heard learned counsel for parties. By two notifications of Central Government (No. S. O. 1028(E), dated November 7, 1988, and No. S. O. 148(E), dated February 28, 1989), Income- tax Act, 1961, was extended to State of Sikkim with effect from April 1, 1989, i.e., from assessment year 1989-90. However, after some practical difficulty, section 26 of Finance Act, 1989, made statutory provisions for application of Income-tax Act, 1961, to State of Sikkim that notwithstanding anything contained in above two notifications issued by Government of India, so far as they relate to commencement of Income-tax Act, 1961, in State of Sikkim with effect from previous year relevant to assessment year commencing on 1st day of April, 1990, provisions of Income-tax Act, 1961, shall come into force in State of Sikkim with effect from previous year relevant to assessment year commencing on 1st day of April, 1990, and any law corresponding to Income-tax Act, 1961, which, immediately before such commencement, was in force in State of Sikkim shall be deemed to have effect in relation to previous year beginning with 1st day of April, 1988, and ending with 31st day of March, 1989, and shall continue in force for purpose of levy, assessment and collection of income-tax or for purpose of imposing any penalty or for any other purposes whatsoever connected with, or incidental to any of purposes aforesaid under such law. Thereafter, making clarification on point of commencement of Income-tax Act, 1961, in State of Sikkim, Circular bearing No. 550 (see [1990] 182 ITR (St.) 114) (annexure P3) was issued and it was clarified that such provision under section 26 of Finance Act, 1989, became necessary as earlier notification issued by Ministry of Home Affairs had extended Income-tax Act, 1961, to State of Sikkim with effect from April 1, 1989, i.e., from assessment year 1989-90 and, accordingly, law already in existence in State of Sikkim stood repealed from April 1, 1988. matter relating to application of Income-tax Act, 1961, and Sikkim State Income-tax Manual, 1948, however, remained in controversy for long period between two Governments and Committee was constituted to resolve issue of implementation of Income-tax Act, 1961, in Sikkim, which conducted meeting on April 20, 2007, in Delhi. minutes of meeting chaired by member (Inv.), CBDT, Government of India (GOI) has been filed as annexure R1. deliberations on issue No. (iv) would show that it was indicated by Chairman that though Income-tax Act, 1961, was extended to Sikkim with effect from assessment year 1989-90 by President of India in exercise of power under clause (n) of article 371F of Constitution of India, due to difficulties pointed out by Government of Sikkim, implementation of Income-tax Act, 1961, was deferred by one year (assessment year 1989-90 to assessment year 1990-91) and due to this, Sikkim State Incometax Manual, 1948, stood repealed automatically from date in view of clause (k) of article 371F of Constitution of India. It was clearly indicated by Chairman that levy of income-tax as per Sikkim State Income-tax Manual, 1948, after April 1, 1990, was unconstitutional. On clarification being sought by officers of Government of Sikkim that whether it was required that provisions for repealing of Sikkim State Income-tax Manual, 1948, could be included in Income-tax Act, 1961, Chairman clarified that, according to Central Government's view, Sikkim State Income-tax Manual, 1948, stood repealed automatically once Income- tax Act, 1961, being Central legislation, was extended to Sikkim. Thereafter, Government of India formulated package comprising 10 (ten) points, dated August 20, 2007 (annexure R2), and communicated same to Chief Secretary of Government of Sikkim, containing point No. (V) that Sikkim State Income-tax Manual, 1948, would stand repealed with effect from assessment year 1990-91 relevant to previous year beginning on April 1, 1989. In reply to said communication dated August 20, 2007, State Government accepted above proposal and communication dated August 21, 2007 (annexure R3), in this regard, was sent to Government of India. Then resolution (annexure R4) was passed on direct tax laws adopted by Sikkim Legislative Assembly on June 10, 2008, which also indicates that Sikkim State Income-tax Manual, 1948, would stand repealed by implication. Neither above documents nor above events have been disputed by any party. Therefore, it is clear that on stand taken by both Governments, Sikkim State Income-tax Manual, 1948, stood repealed on April 1, 1990, by necessary implication, after extension of Incometax Act, 1961, to State of Sikkim. However, it still requires to be tested for determination of correct legal position in this regard as law(s) neither operate nor cease to operate on admission of parties and they have to be interpreted for every purpose, including its commencement, enforcement, continuance, repeal and other like instances, when required, on various provisions contained therein and contemporary laws and principles of interpretation. Mr. Pal has argued that even if we ignore admissions of concerned Government, deep analysis of both enactments would show that Sikkim State Income-tax Manual, 1948, was impliedly repealed from April 1, 1990, on extension of Income-tax Act, 1961, in State of Sikkim. In fact, he emphasised on doctrine of implied repeal. doctrine of implied repeal is concept in constitutional theory, which states that where Act conflicts with earlier one, later Act takes precedence and conflicting parts of earlier Act are repealed. This doctrine is expressed in Latin phrase leges posteriores priores contrarias abrogant, which means "later laws repeal earlier laws inconsistent therewith" (vide Broom's Legal Maxims, tenth edition, page 347). Implied repeal is to be contrasted with express repeal by Legislature. continuance of existing legislation, in absence of express provision of repeal, is always presumed. presumption is, however, rebutted and repeal is inferred by necessary implication when provisions of later Act are so inconsistent with or repugnant to provisions of earlier Act "that two cannot stand together" (vide Principles of Statutory Interpretation by Justice G. P. Singh, ninth edition 2004, page 568). In Municipal Corporation of Delhi v. Shiv Shanker [1971] 1 SCC 442, it was held that Legislature, which may generally be presumed to know existing law, is not expected to intend to create confusion by its omission to express its intent to repeal in clear terms. courts, therefore, as rule, lean against implying repeal unless two provisions are so plainly repugnant to each other that they cannot stand together and it is not possible on any reasonable hypothesis to give effect to both at same time. repeal must, if not express, flow from necessary implication as only intendment. provisions must be wholly incompatible with each other so that two provisions operating together would lead to absurd consequences, which intention could not reasonably be imputed to Legislature. It is only when consistent body of law cannot be maintained without abrogation of previous law that plea of implied repeal should be sustained. To determine if later statutory provision repeals by implication earlier one it is accordingly necessary to closely scrutinise and consider true meaning and effect both of earlier and later statute. Until this is done it cannot be satisfactorily ascertained if any fatal inconsistency exists between them. meaning, scope and effect of two statutes, as discovered on scrutiny, determines legislative intent as to whether earlier law shall cease or shall only be supplemented. If objects of two statutory provisions are different and language of each statute is restricted to its own objects or subject, then they are generally intended to run in parallel lines without meeting and there would be no real conflict though apparently it may appear to be so on surface. Statutes in pari materia although in apparent conflict, should also, so far as reasonably possible, be construed to be in harmony with each other and it is only when there is irreconcilable conflict between new provision and prior statute relating to same subject matter, that former, being later expression of Legislature, may be held to prevail, prior law yielding to extent of conflict. In R. S. Raghunath v. State of Karnataka, AIR 1992 SC 81, it was held that there should be clear inconsistency between two enactments before giving overriding effect to non obstante clause but when scope of provisions of earlier enactment is clear same cannot be cut down by resort to non obstante clause. observations made in Municipal Council, Palai v. T. J. Joseph, AIR 1963 SC 1561, was also taken note of in this judgment, which reads that there is presumption against repeal by implication; and reason of this rule is based on theory that Legislature while enacting law has complete knowledge of existing laws on same subject matter and, therefore, when it does not provide repealing provisions, it gives out intention not to repeal existing legislation. It is further observed that such presumption can be rebutted and repeal by necessary implication can be inferred only when provisions of later Act are so inconsistent with or repugnant to provisions of earlier Act, that two cannot stand together. In State of M. P. v. Kedia Leather and Liquor Ltd. [2003] 7 SCC 389, taking note of above decisions and many others, it was held that there is presumption against repeal by implication; and reason of this rule is based on theory that Legislature while enacting law has complete knowledge of existing laws on same subject matter, and, therefore, when it does not provide repealing provision, intention is clear not to repeal existing legislation. When new Act contains repealing section mentioning Acts which it expressly repeal, presumption against implied repeal of other laws is further strengthened on principle expression unius (persone vel rei) est exclusion alterius (The express intention of one person or thing is exclusion of another). continuance of existing legislation, in absence of express provision of repeal by implication lies on party asserting same. presumption is, however, rebutted and repeal is inferred by necessary implication when provisions of later Act are so inconsistent with or repugnant to provisions of earlier Act that two cannot stand together. But, if two can be read together and some application can be made of words in earlier Act, repeal will not be inferred. necessary questions to be asked are: (1) Whether there is direct conflict between two provisions. (2) Whether Legislature intended to lay down exhaustive code in respect of subject matter replacing earlier law. (3) Whether two laws occupy same field. When court applies doctrine, it does no more than give effect to intention of Legislature by examining scope and object of two enactments and by comparison of their provisions. matter in each case is one of construction and comparison of two statutes. court leans against implying repeal. To determine whether later statute repeals by implication earlier statute, it is necessary to scrutinise terms and consider true meaning and effect of earlier Act. Until this is done, it is impossible to ascertain whether any inconsistency exists between two enactments. In instant case, Income-tax Act, 1961, was already in force, which was extended to State of Sikkim on April 1, 1990. Thus, it was not instance of enacting new taxation law for State of Sikkim after it became part of India. Therefore, principle that Legislature, while enacting law, has complete knowledge of existing laws on same subject matter and possible consequence thereof would not be applicable. In such situation, if it does not provide repealing provision, only by this, it cannot be held that intention was not to repeal existing legislation. If we examine situation in light of principles, referred to above, we find that provisions of two enactments are quite different and both enactments cannot stand together. Income-tax Act, 1961, is exhaustive than Sikkim State Income-tax Manual, 1948, and, as is clear from provisions of both enactments, they occupy same field relating to levy of income-tax and its recovery. Thus, if both enactments are held to be applicable, it shall create great anomaly. There is yet other reason to take this view, that is, if both statutes are held to be operating in same field, there would be situation of existing two laws relating to income-tax and in absence of any protection coming forward, assessees may be subjected to double taxation. It is, thus, clear that on account of above inconsistencies, two enactments cannot stand together and we have no hesitation in holding that on extension of Income-tax Act, 1961, Sikkim State Income-tax Manual, 1948, was repealed by necessary implication. So far as arguments relating to estoppel, quoted in paragraph 4 (supra), raised by learned Additional Advocate General is concerned, we may note that estoppel is rule of evidence which bars party from denying or alleging certain facts owing to his/its previous conduct, allegation, or denial. It is well settled that there could not be estoppel against statutes. One cannot be prevented by any estoppel from ascertaining his rights under particular Act/statute so long said Act/statute continues to be law in force. There may be many reasons like wrong advice, ignorance, confusion or not correctly understanding law or rights, for party to take pleadings against his rights under Act or statute, which he/it can always correct either in same proceeding or in any subsequent proceeding and take plea according to his/its rights under Act/statute. We may also note that in earlier matter, nothing was finally determined by court. writ petition was filed, ad interim order was taken and ultimately, it was withdrawn with liberty to approach to competent authority/forum for redressal of grievances stated in writ petition. Thus, above controversy was not finally determined by court. Learned Additional Advocate General also argued on doctrine of approbation and reprobation. This is general principle that party cannot be allowed to approbate and reprobate. It is based on maxim allegans contraria non est audiendus, which means "He is not to be heard who alleges things contradictory to each other" (vide Broom's Legal Maxims (supra) page 103). But before applying this doctrine one must ascertain that there has to be estoppel in one form or other. If there is no estoppel, there would be no question of doctrine coming into operation (vide Nagubai Ammal v. B. Shama Rao, AIR 1956 SC 593). In CIT v. V. MR. P. Firm, Muar [1965] 56 ITR 67 (SC); AIR 1965 SC 1216 , it was held that doctrine of "approbate and reprobate" is only species of estoppels; it applies only to conduct of parties. As in case of estoppel it cannot operate against provisions of statute. If particular income is not taxable under Income-tax Act, it cannot be taxed on basis of estoppel or any other equitable doctrine. Equity is out of place in tax law; particular income is either exigible to tax under taxing statute or it is not. If it is not, Income- tax Officer has no power to impose tax on said income. In instant case, we have already held that Sikkim State Incometax Manual, 1948, stood repealed after extension of Income-tax Act, 1961, in State of Sikkim with effect from April 1, 1990. petitioner has come claiming its rights as assessee under Income-tax Act, 1961. Therefore, any adverse plea like it was not assessee under this Act or that Income-tax Act, 1961, was not applicable to petitioner, being plea relating to statute would not operate as estoppel against it and arguments advanced by Additional Advocate General is to be rejected. It is, thus, clear from material placed before us that, firstly, petitioner approached this court by filing writ petition, saying that Incometax Act, 1961, was not applicable, but, said writ petition was withdrawn with liberty to approach to competent authority/forum and, thereafter, petitioner succumbed to income-tax authorities under Incometax Act, 1961, and presently, various proceedings are pending before appropriate forums under said Act. above facts with specifications are widely stated in paragraphs 3 and 4 of counter-affidavit filed by Union of India/respondent No. 4. petitioner has also claimed refund of Rs. 76,63,655 together with interest till date of realisation. During course of arguments, Mr. Pal, on instructions, fairly conceded that previous interest or interest pendente lite on said amount may not be awarded to petitioner but State may be directed to refund this amount within time-frame prescribed by this court. Therefore, we are not deliberating on this point, however, we would prefer to issue appropriate direction in this regard. For foregoing reasons, we allow this writ petition and record our findings that after extension of Income-tax Act, 1961, to State of Sikkim with effect from April 1,1990, Sikkim State Income-tax Manual, 1948, stands repealed and assessments made thereunder for accounting years 1996- 97 to 2004-05 (assessment years 1997-98 to 200506) are without authority of law, non est and nullity. Consequently, impugned order dated July 7, 2006 (annexure P6), demand notice dated July 7, 2006 (annexure P7) and other consequential orders/memos thereto are quashed. State-respondents are directed to refund sum of Rs. 76,53,655 to petitioner within period of 90 (ninety) days from today, failing which this amount shall carry interest at 6 per cent. per annum from date commencing after completion of 90 (ninety) days till realisation. No order as to costs. *** Sikkim Manipal University v. State of Sikkim