JUDGMENT S.C. Das, J.:- By filing this writ petition the petitioner, inter alia prayed for directing the respondents to regularize his service w.e.f. 20.07.1998, the date of his first appointment on adhoc basis, and also to provide him all service benefits including the benefit of Career Advancement Scheme-I(CAS-I, for short) in the post of Senior Research Officer(for short, SRO) and also prayed for setting aside Memo. dated 19.09.2005(Annexure-7 to the writ petition) under which the respondents directed the petitioner to deposit an amount of ` 6,843/- alleging that the said amount was excess drawn by the petitioner during the period from 07.05.2005 to 31.08.2005. 2. Heard learned counsel, Mrs. S. Deb(Gupta) for the petitioner and learned State counsel, Mr. A. Ghosh for respondent Nos. 1 and 2. None appeared for respondent No. 3. 3. Succinct facts, leading to filing of the present writ petition, are recapitulated: 3.1. Pursuant to an advertisement, dated 01.11.1995 (Annexure-1 to the writ petition) by the Director of Higher Education, Government of Tripura, for the post of SRO, reserved for the Scheduled Castes category candidates, the petitioner applied for the post and through selection process, under the Special Drive for Recruitment of Scheduled Castes and Scheduled Tribes candidates, against the vacant posts, the petitioner was selected for the post of SRO and vide Memo. dated 13.07.1998(Annexure-3 to the writ petition), offer was given to the petitioner and the petitioner accepted the offer and joined the post of SRO on adhoc basis on 20.07.1998. He was thereafter transferred to the Directorate of School Education and was serving under the department with all sincerity and devotion. 3.2. While the petitioner was clamouring for his regularization of adhoc appointment, after four years of service he was moved to the scale of ` 10,000-15,100/- in the year 2002. Thereafter, the respondents regularized the service of the petitioner vide Notification dated 06.05.2005(Annexure-6 to the writ petition) in the pay scale of ` 7,800-15,100/-. The petitioner joined the regular post on 07.05.2005 and his pay was fixed at ` 9,480/- on 07.05.2005 and the respondents by Memo. dated 19.09.2005(Annexure-7 to the writ petition) directed that an amount of ` 6,843/- was paid to the petitioner in excess and directed him to deposit the said amount. 3.3. The petitioner joined the regular post on 07.05.2005 and his pay was fixed at ` 9,480/- on 07.05.2005 and the respondents by Memo. dated 19.09.2005(Annexure-7 to the writ petition) directed that an amount of ` 6,843/- was paid to the petitioner in excess and directed him to deposit the said amount. 3.3. It is the case of the petitioner that he was expecting regularization w.e.f. 20.07.1998 but he was given prospective regularization w.e.f. 06.05.2005, and, as a result his interest in respect of his seniority and remuneration, both were seriously affected and the petitioner was thereby deprived of his right guaranteed under Articles 14 and 16 of the Constitution of India. He made a representation on 30.05.2005 claiming his regularization w.e.f. 20.07.1998 and copy of that representation annexed as Annexure-8 to the writ petition. The petitioner claimed that under a special drive for recruitment of SC and ST candidates, against existing vacancy, pursuant to the open advertisement made, the petitioner participated in the selection process and accordingly as against the vacant post of SRO, the petitioner got selection and was appointed on adhoc basis and he served continuously without any interruption. As per ROP Rules, 1990, CAS-I was also given to him in the year 2002, on his completion of four years of service from 20.07.1998, and, he was entitled to be regularized with effect from the date of initial appointment, i.e. 20.07.1998. After regularization, his pay cannot be reduced and the respondents should not have asked him to return any amount which was already given to him by the department pursuant to ROP Rules, 1999. The petitioner, therefore, prayed for directing the respondents to regularize his services w.e.f. 20.07.1998 and also prayed for setting aside Memo. dated 19.09.2005 under which he has been asked to deposit the amount of ` 6,843/-. 4. Respondent Nos. The petitioner, therefore, prayed for directing the respondents to regularize his services w.e.f. 20.07.1998 and also prayed for setting aside Memo. dated 19.09.2005 under which he has been asked to deposit the amount of ` 6,843/-. 4. Respondent Nos. 1 and 2, inter alia, contended that the petitioner was appointed in the post of SRO on adhoc basis w.e.f. 20.07.1998 under a special drive recruitment for the Scheduled Castes and Scheduled Tribes candidates through open advertisement in the local daily newspaper and the petitioner was inducted in the service on adhoc basis under specific terms and conditions that the adhoc appointment will not bestow upon the petitioner any claim for regular appointment and that the adhoc service rendered by him would not be counted for the purpose of seniority in the grade and his eligibility for promotion, confirmation, etc. The appointee will have to face the TPSC on the basis of the notification of advertisement as and when made/published by the Commission for selection to the post of SRO. The appointment will stand automatically cancelled or will be deemed to have terminated unless he is selected by the Tripura Public Service Commission. The appointment was initially for a period of six months. It is contended by the respondents that knowing fully well all the terms and conditions of adhoc appointment the petitioner accepted the offer which is reflected in Annexure-3 to the writ petition and so the petitioner cannot claim regularization from the date of his adhoc appointment, i.e. 20.07.1998. While the petitioner was in adhoc service, after completion of four years of service to the post of SRO, he was allowed the higher pay scale of ` 10,000-15.100/- due to oversight. It was a bona fide mistake committed by the department and a bona fide mistake can always be corrected through official process, and therefore, after regularization of his appointment, he was given the pay scale of ` 7,800-15,100/-, which was actually admissible to the petitioner in the post of SRO. It is also contended by the respondents that at the relevant point of time of appointment of the petitioner in the post of SRO there was no official final recruitment rule and a recruitment rule was finalized only on 02.11.2004. It is also contended by the respondents that at the relevant point of time of appointment of the petitioner in the post of SRO there was no official final recruitment rule and a recruitment rule was finalized only on 02.11.2004. As per the provision of the recruitment rule, the post of SRO should be filled up by promotion from the feeder post of Statistical Officer/Evaluation Officer with five years of service in the post and otherwise by direct recruitment with the qualification of master degree or honours graduate in Statistics/Mathematics/Physics/Sociology/Economics from a recognized university. The petitioner was not having with the requisite qualification being a simple graduate and, therefore his adhoc services could not be regularized at once. The department moved the Tripura Public Service Commission for regularization of the services of the petitioner to the post of SRO as a special case and, accordingly, TPSC vide Memo. No. F.66(110)-TPSC/2005 dated 19.04.2005 approved the proposal and accordingly his services was regularized vide Memo. dated 06.05.2005 and he joined the regular post on 07.05.2005. His pay was also fixed in the regular post w.e.f. 07.05.2005 in the pay scale of Rs. 7,800-15,100/-. While fixing the salary of the petitioner there was a bona fide mistake in calculation during the period from 07.05.2005 to 31.08.2005 and an excess amount of ` 6,843/- was paid to the petitioner which the petitioner was bound to return and accordingly vide Memo. dated 19.09.2005(Annexure-7 to the writ petition) the petitioner was asked to return the amount. The writ petition has been unnecessarily filed seeking illegal gain and, therefore liable to be dismissed. 5. It is an admitted position that the respondents, under a special recruitment drive for ST and SC candidates against vacant posts under the Government of Tripura, made open advertisement published in widely circulated daily newspapers asking application from the eligible candidates for different posts under the Directorate of Higher Education, Government of Tripura and one of the post, for which the advertisement was made, was of Senior Research Officer meant for Scheduled Castes category candidates. Annexure-1 and Annexure-2 are the advertisements which are not in dispute. It is also an admitted position that pursuant to that advertisement the petitioner applied for the post of SRO and under a due selection process the petitioner was selected and was appointed in the post of SRO w.e.f. 20.07.1998 on adhoc basis. Annexure-1 and Annexure-2 are the advertisements which are not in dispute. It is also an admitted position that pursuant to that advertisement the petitioner applied for the post of SRO and under a due selection process the petitioner was selected and was appointed in the post of SRO w.e.f. 20.07.1998 on adhoc basis. It is also an admitted position that the adhoc service of the petitioner was regularized by notification dated 06.05.2005(Annexure-6 to the writ petition) in the pay scale of ` 7,800-15,100/- and the petitioner joined the post on 07.05.2005. It is also an undisputed fact that the petitioner was appointed on adhoc basis in the year 1998 in the pre-revised pay scale of ` 2,100-5,000/- and that scale was subsequently revised to the scale of ` 7,800- Rs. 15,100/- after ROP Rules, 1999. It is an admitted position that ROP Rules, 1999 prescribes movement to CAS-I after four years of service and it is an admitted position that after four years of service the petitioner was given scale of ` 10,000-15,100/- from the year 2002, however, the respondents contended that it was given through oversight. 6. It is submitted by learned counsel, Mrs. Deb(Gupta) that the petitioner was in public employment before his appointment to the post of SRO on adhoc basis. Pursuant to the open advertisement under Special Drive for Recruitment Of SC & ST candidates against vacant posts the petitioner participated in the selection process and he was given appointment on adhoc basis but that adhoc appointment was not dehors the rule rather it was against a vacancy and the selection of the petitioner was made after due process and so the petitioner was entitled to be regularized from the date of his first appointment on adhoc basis. 6.1. It is also contended by learned counsel, Mrs. Deb(Gupta) that at the time of appointment of the petitioner there was no service rule for appointment to the post of SRO in the year 1998. The service rule was made in the year 2004. So, the provisions of the service rule of 2004 cannot be applied in the case of the petitioner and the petitioner was entitled to be regularized in the post from the date of his adhoc appointment and he should be given all service benefits accordingly. 6.2. The service rule was made in the year 2004. So, the provisions of the service rule of 2004 cannot be applied in the case of the petitioner and the petitioner was entitled to be regularized in the post from the date of his adhoc appointment and he should be given all service benefits accordingly. 6.2. Referring to the judgment in WP(C) No. 284 of 2003, Bir Chandra Debbarma v. The State of Tripura & Anr. passed by a Single Judge of the Agartala Bench of the Gauhati High Court, learned counsel, Mrs. Deb(Gupta) submits that this case and the case of Bir Chandra Debbarma(supra) stand on similar facts and on similar and identical points and this case is a covered case of the case of Bir Chandra Debbarma(supra). In view of that decision in the case of Bir Chandra Debbarma(supra), which is not challenged by the State respondents, the present writ petition filed by the petitioner should be allowed. 7. Learned State counsel, Mr. Ghosh has submitted that the petitioner was appointed on adhoc basis under specific terms and conditions as stipulated in Memo. dated 13.07.1998(Annexure-3 to the writ petition) and once the petitioner accepted all those terms and conditions he cannot claim regularization in the service as of right with effect from the date of his adhoc appointment. It is also contended by Mr. Ghosh, learned counsel that the petitioner was regularized by notification, dated 06.05.2005 prospectively in the pay scale of ` 7,800-15,100/- which was the pay scale meant for SRO and the petitioner joined the post on 07.05.2005. While fixing the salary of the petitioner there were some mistake occurred inadvertently and an amount of ` 6,843/- was excess paid to the petitioner during the period from 07.05.2005 to 31.08.2005 and by the impugned order dated 19.09.2005 the authority regularized the discrepancy and directed the petitioner to deposit the excess amount. There was nothing wrong in such direction and the petitioner was duty bound to re-deposit the amount. 8. Admittedly, there was no service rule for appointment to the post of SRO at the relevant point of time when the petitioner was appointed in the year 1998. Indisputably, the service rule came into existence in the year 2004 and so the recruitment process of the petitioner cannot be guided by the service rule which was admittedly made long after the appointment of the petitioner. Indisputably, the service rule came into existence in the year 2004 and so the recruitment process of the petitioner cannot be guided by the service rule which was admittedly made long after the appointment of the petitioner. In the service rule certain academic qualification was prescribed which the petitioner was not having when he was appointed and since there was no rule at that point of time and the petitioner applied pursuant to the open advertisement made, he cannot be found with any fault and the provisions of service rules in respect of qualification cannot be applied in the case of the petitioner and consequently the petitioner cannot be termed as not having with the requisite qualification at the time of his appointment. 9. It is an admitted position that the petitioner was appointed on 20.07.1998 in the post of SRO on adhoc basis under the following terms and conditions:- (1) This appointment is purely on temporary basis for a period of 6(six) months from the date of joining. (2) This adhoc appointment will not bestow upon the person a claim for regular appointment and that adhoc service rendered would not be counted for the purpose of seniority in the grade and for eligibility for promotion, confirmation etc. (3) The appointee will have to face the Tripura Public Service Commission on the basis of the Notification of advertisement as and when made/published by the Commission for selection to the post of Senior Research Officer. This appointment stands automatically cancelled or is deemed to have been terminated from services unless he is selected by the Tripura Public Service Commission. 9.1. It is also an admitted position that the petitioner was appointed after an open advertisement under a special drive for recruitment of Scheduled Castes and Scheduled Tribes candidates by the Government against a vacant post through regular selection process. 9.2. It is trite that the term, ’adhoc’ means ’fortuitous’ or ’stop-gap’ and that it is not possible to lay down any straightjacket formula or exhaustive list of circumstances and situation in which such an appointment can be made. All public appointments in public posts should be made according to the rules and constitutional scheme. A person, appointed dehors the rules in violation of the constitutional scheme, cannot claim regularization of his service. All public appointments in public posts should be made according to the rules and constitutional scheme. A person, appointed dehors the rules in violation of the constitutional scheme, cannot claim regularization of his service. If an adhoc/temporary/contingent/daily basis appointment is made dehors the rules in violation of the constitutional scheme, neither the person so appointed has a right to claim his regularization nor the authority has the jurisdiction to regularize such backdoor appointee. In service jurisprudence, a person who possesses the requisite qualification for being appointed to a particular post and appointment made after proper open advertisement for the post and through a due selection process and continues in the post with all service benefits, then, such appointment cannot be held to be ’stop-gap’ or ’fortuitous’ or ’purely adhoc’ appointment. 10. In the case of Direct Recruit Class II Engineering Officers’ Association v. State of Maharashtra & Ors. reported in (1990) 2 SCC 715 , the apex Court has laid down as follows: (A) Once an incumbent is appointed to a post according to rule, his seniority has to be counted from the date of his appointment and not according to the date of his confirmation. The corollary of the above rule is that where the initial appointment is only ad hoc and not according to rules and made as a stop-gap arrangement, the officiation in such post cannot be taken into account for considering the seniority. (B) If the initial appointment is not made by following the procedure laid down by the rules but the appointee continues in the post uninterruptedly till the regularization of his service in accordance with the rules, the period of officiating service will be counted. 11. The phrase "according to Rules" and the phrase "not made by following the procedure laid down by the Rules" used therein were interpreted by the Apex Court in State of West Bengal v. Aghore Nath Dey & Ors. reported in (1993) 3 SCC 371 . 25. In our opinion, the conclusion (B) was added to cover a different kind of situation, wherein the appointments are otherwise regular, except for the deficiency of certain procedural requirements laid down by the rules. reported in (1993) 3 SCC 371 . 25. In our opinion, the conclusion (B) was added to cover a different kind of situation, wherein the appointments are otherwise regular, except for the deficiency of certain procedural requirements laid down by the rules. This is clear from the opening words of the conclusion (B), namely, ’if the initial appointment is not made by following the procedure laid down by the ’rules’ and the latter expression ’till the regularisation of his service in accordance with the rules’. We read conclusion (B), and it must be so read to reconcile with conclusion (A), to cover the cases where the initial appointment is made against an existing vacancy, not limited to a fixed period of time or purpose by the appointment order itself, and is made subject to the deficiency in the procedural requirements prescribed by the rules for adjudging suitability of the appointee for the post being cured at the time of regularisation, the appointee being eligible and qualified in every manner for a regular appointment on the date of initial appointment in such cases. Decision about the nature of the appointment, for determining whether it falls in this category, has to be made on the basis of the terms of the initial appointment itself and the provisions in the rules. In such cases, the deficiency in the procedural requirements laid down by the rules has to be cured at the first available opportunity, without any default of the employee, and the appointee must continue in the post uninterruptedly till the regularisation of his service, in accordance with the rules. In such cases, the appointee is not to blame for the deficiency in the procedural requirements under the rules at the time of his initial appointment, and the appointment not being limited to a fixed period of time is intended to be a regular appointment, subject to the remaining procedural requirements of the rules being fulfilled at the earliest. In such cases also, if there be any delay in curing the defects on account of any fault of the appointee, the appointee would not get the full benefit of the earlier period on account of his default, the benefit being confined only to the period for which he is not to blame. In such cases also, if there be any delay in curing the defects on account of any fault of the appointee, the appointee would not get the full benefit of the earlier period on account of his default, the benefit being confined only to the period for which he is not to blame. This category of cases is different from those covered by the corollary in conclusion (A) which relates to appointment only on ad hoc basis as a stopgap arrangement and not according to rules. It is, therefore, not correct to say, that the present cases can fall within the ambit of conclusion (B), even though they are squarely covered by the corollary in conclusion (A). 12. Observation of the apex Court quoted above makes it abundantly clear that the instant case of the petitioner, is covered by the conclusion(B) since the petitioner was appointed on special recruitment drive for the Scheduled Castes and Schedules Tribes against existing vacancy and through a due selection process. Consultation with TPSC was a procedural formality to be observed by the respondents which may fairly be inferred from the Government notification in Annexure-5 wherein conscious decision was taken by the Government that in case of availability of SC/ST candidates the reserved posts should invariably be filled up(both promotion and direct recruitment) by 25.11.95. If it is not possible to give regular appointment to the reserved category of candidates after following all required formalities appointment should be issued on adhoc basis pending regularization of the appointments subsequently through due course and procedure. The petitioner applied for the post pursuant to an open advertisement made by the respondents for the post of SRO. He was appointed after a due selection process, undertaken by the respondents. There was no service rule for appointment to the post of SRO at the relevant point of time. The petitioner was having with requisite qualification as required in the advertisement and, accordingly his candidature was entertained and he was selected. There was vacant post for which the selection process was undertaken and the appointment was made. The petitioner was given appointment on adhoc basis under some specific terms and conditions and he continued in the post for long time without any interpretation and enjoyed all service benefits. So, the petitioner cannot be said to have appointed through backdoor without following a transparent procedure. The petitioner was given appointment on adhoc basis under some specific terms and conditions and he continued in the post for long time without any interpretation and enjoyed all service benefits. So, the petitioner cannot be said to have appointed through backdoor without following a transparent procedure. Since he was appointed in a vacant post after open advertisement through a regular selection process and he continued in the post and enjoyed all service benefits his adhoc appointment cannot be termed as a backdoor appointment or an appointment made dehors the rule violating the constitutional scheme. 13. The case of Bir Chandra Debbarma(supra), referred by learned counsel, Mrs. Deb(Gupta) for the petitioner, is identical to that of the present case. It was also a case against the same set of respondents. Identical issue was decided in that writ petition. The petitioner of that case was also an adhoc appointee under special drive for recruitment of SC/ST candidates and he was subsequently regularized with prospective effect and his representation for giving him regularization from the date of his adhoc appointment was refused and the High Court directed the respondents to give the benefit of retrospective effect from the date of adhoc appointment. Learned State counsel failed to show any material that the said decision in the case of Bir Chandra Debbarma(supra) is not in force. In paras 8 and 9 of the judgment, the learned single Judge observed: 8. The aforesaid observations of the Apex Court are self explanatory. The question then is, whether the case of the petitioner in the instant case is covered by conclusion(A) or conclusion(B). Reverting to the instant case, the petitioner was without dispute appointed on a special recruitment drive for Scheduled Castes and Scheduled Tribes, against an existing vacancy and on the recommendation of the Screening Board after due advertisement. There is no dispute that the petitioner was qualified for the post of Lecturer to the post in which he was initially appointed in terms of the Recruitment Rules in force which, as noticed above, was the rule applicable. In that view of the matter, the petitioner cannot be held to be appointed through backdoor. By making advertisement all the reserved candidates were deemed to have been duly notified. In that view of the matter, the petitioner cannot be held to be appointed through backdoor. By making advertisement all the reserved candidates were deemed to have been duly notified. In Jagbir Singh V. State of Haryana and others, (1996) 11 SCC 752 , it was held by the Apex Court that a Constable recruited in Haryana Police Service against sports quota was regular appointee and not ad hoc appointee. The only deficiency in the appointment of the petitioner in the instant case appears to be the non-recommendation/non-approval by the TPSC of his appointment. It is quite evident that the procedural requirement of non-approval/non-recommendation by the TPSC has not been fulfilled due to the fault of the State-respondents, for which the petitioner can hardly be faulted with. Under the circumstances, the case of the petitioner cannot come within the conclusion(A) of Direct Recruit Class II Engineering Officers’ Association case(Supra) but will undoubtedly come within the four corners of conclusion(B) thereof. The subsequent regularization of the service of the petitioner done with the approval of the council of Ministers appears to be immaterial inasmuch as the petitioner was not appointed in accordance with the Recruitment Rules of 2002 but was appointed in accordance with the Rules of 1984 whereunder the petitioner was admittedly qualified for the post. There was no justification for the State-respondents not to place the case of the petitioner before the TPSC for regularizing his ad hoc service in time and had that been done and if the approval obtained, which can only be a routine matter, the regularization of the petitioner would have been made with effect from the date of his initial ad hoc appointment. Under the circumstances, the action of the State-respondents in not giving retrospective regularization to the petitioner with effect from 11.09.1996 is arbitrary and illegal. Alternatively, the State respondents, having regularized the service of the petitioner by relaxing the qualification in terms of the Recruitment Rules, 2002 could have given retrospective regularization to the petitioner from the date of his initial appointment in view of the facts that his appointment was made on the recommendation of the Screening Committee after the post was duly advertised and against an existing vacancy for which he was eligible under the Recruitment Rules then in force. 9. In the light of the foregoing discussion, this writ petition is allowed. 9. In the light of the foregoing discussion, this writ petition is allowed. The State-respondents are hereby directed to regularize the ad hoc appointment of the petitioner to the post of Lecturer, DIET with effect from 23.11.1996 for the purpose of seniority and promotion. The notification dated 23.11.2001(Annexure-3) stands read down accordingly. The entire exercise shall be completed by the State-respondents, particularly by the respondent No. 2, within 2(two) months from the date of receipt of this judgment. The above observation of the learned Single Judge in Bir Chandra Debbarma(supra) may be fairly applied in the facts and legal position of the present case and I find nothing to arrive at a contrary finding. 14. In view of the discussions made above the writ petition is allowed. Respondents are directed to give the benefit of regularization of service to the petitioner from the date of his adhoc appointment, i.e. 20.07.1998, pursuant to Annexure-3 to the writ petition and to provide him all other service benefits as per rules. The direction of the respondents through Annexure-9(Memo. dated 19.09.2005) directing the petitioner to deposit excess amount stands quashed. 15. The respondents are directed to comply the order within sixty days from today. 16. Parties to bear their own costs.