ORDER 1. Leave granted. 2. We have heard the learned counsel for the parties. 3. The appellant, B. D. Verma, was appointed on the post of Junior Computer in the Ministry of Irrigation and Power of the Government of India in 1959 and was confirmed on the said post on 7-4-1966. He was promoted to the post of Senior Computer on 20-7-1962 and was confirmed on the said post with effect from 17-9-1974. He was promoted as Research Assistant (Statistics) on ad hoc basis on 1-9-1974. He continued to work as Research Assistant on ad hoc basis till 5-1-1985 when he was regularly promoted on the said post of Research Assistant on the basis of the recommendation of the Departmental Promotion Committee which met in 1984. Bansilal Bapurao Khandekar and Rasheed Ahmad Mia were appointed by direct recruitment as Research Assistants by orders dated 9-12-1985 and 17-12-1985 respectively. On 17-1-1986, a seniority list of officers borne on the cadre of Statistical Assistants/Professional Assistants (Statistics) /Research Assistants (Statistics) in the Central Water a Commission, as on 1-1-1986, was issued wherein the appellant was placed at Serial No. 22 while Bhansilal Bapurao Khandekar and Rasheed Abmad Mia were placed at Serial Nos. 19 and 21 respectively. The appellant submitted representations with regard to the fixing of his seniority and claimed that the period of ad hoc service rendered by him on the post of Research Assistant must be counted for the purpose of seniority. He also submitted that the condition of probation for a period of two years should not be applied to him. The said representations of the appellant were, however, rejected by order dated 7-7-1988. On 3-2-1989, the appellant filed an application (OA No. 437 of 1989) before the Central Administrative Tribunal, Principal Bench, Delhi (hereinafter referred to as the Tribunal") wherein he assailed the order dated 7-7-1988. 4. Prior to the filing of the said application by the appellant, two Research Assistants, Harpal Singh and Sital Das, had filed an application (OA No. 1783 of 1988) before the Tribunal seeking the relief of counting the period of their ad hoc service as Research Assistant for the purpose of seniority in the cadre of Research Assistants. Harpal Singh and Sital Das were junior to the appellant in the cadre of Senior Computers. Harpal Singh and Sital Das were junior to the appellant in the cadre of Senior Computers. Though Harpal Singh was promoted as Research Assistant on ad hoc basis on 17-9-1974, on the same date as the appellant, he was reverted to the post of Senior Computer on 13-3-1978 and he was again reappointed as Research Assistant on ad hoc basis on 23-4-1978. Sital Das was promoted as Research Assistant on ad hoc basis on 3-9-1977. OA No. 1783 of 1988 filed by Harpal Singh and Sital Das was decided by the Tribunal by judgment dated 5-9-1990 and both Harpal Singh and Sital Das were permitted to count the period of their uninterrupted ad hoc service as Research Assistant from 23-4-1978 and 3-9-1977 respectively for the purpose of seniority in the cadre of Research Assistants. Jasvinder Singh, who was also junior to the appellant in the cadre of Senior Computers and who had been promoted as Research Assistant on ad hoc basis on 29-8-1977, filed an application (OA No. 1741 of 1992) before the Tribunal wherein he also sought the relief that the period of his uninterrupted ad hoc service as Research Assistant should be counted for the purpose of his seniority in the cadre of Research Assistants. The said application of Jasvinder Singh was allowed by the Tribunal by judgment dated 31-3-1983 and the Tribunal directed that Jasvinder Singh should be given seniority in the cadre of Research Assistants for the purpose of eligibility for promotion to the next higher grade with effect from the date of his ad hoc promotion, i.e., from 29-8-1977. 5. OA No. 437 of 1989 submitted by the appellant came up for consideration before the Tribunal after the aforementioned two matters had been decided. The appellant placed reliance on the decisions of the Tribunal in those cases and claimed the same relief which was granted to his juniors, viz., Harpal Singh, Sital Das and Jasvinder Singh. The Tribunal has, however, declined to give the same relief to the appellant on the vieo that since the appellant had not served on ad hoc basis for a period of 15 to 20 years, he is not covered by proposition B laid down in the case of Direct Recruit Class II Engineering Officers Assn. v. State of Maharashtra ( (1990) 2 SCC 715 : 1990 SCC (L&S) 339 : (1990) 13 ATC 348) 6. v. State of Maharashtra ( (1990) 2 SCC 715 : 1990 SCC (L&S) 339 : (1990) 13 ATC 348) 6. Shri Ranjit Kumar, the learned counsel appearing for the appellant, has submitted that having regard to the fact that the Tribunal in its earlier judgments in OA No. 1783 of 1988 filed by Harpal Singh and Sital Das and OA No. 1741 of 1992 filed by Jasvinder Singh has granted the relief of counting the period of their ad hoc service as Research Assistant for the purpose of seniority in the cadre of Research Assistants, the Tribunal erred in denying the same relief to the appellant who is an officer similarly situate as those officers and, in fact, was senior to all three of them in the cadre of Senior Computers. In this regard, Shri Ranjit Kumar has invited our attention to the seniority list which was issued on 17-1-1986 and has pointed out that while the appellant was placed at Serial No. 22 in that list, Jasvinder Singh, Sital Das and Harpal Singh were placed at Serial Nos. 28, 34 and 38 respectively. Shri Ranjit Kumar has also submitted that the Tribunal was in error in proceeding on the basis that unless the ad hoc service was for a period of 15 to 20 years, it cannot be counted for the purpose of seniority and has submitted that on that criterion Harpal Singh, Sital Das and Jasvinder Singh also could not have been given the relief of counting the period of their ad hoc service as Research Assistant for the purpose of seniority because their ad hoc service was less than that of the appellant. 7. We do not propose to go into the question whether Harpal Singh, Sital Das and Jasvinder Singh have been rightly given the relief of counting the period of their uninterrupted ad hoc service as Research Assistant for the purpose of seniority because the two judgments of the Tribunal in their cases have not been challenged and have attained finality. 7. We do not propose to go into the question whether Harpal Singh, Sital Das and Jasvinder Singh have been rightly given the relief of counting the period of their uninterrupted ad hoc service as Research Assistant for the purpose of seniority because the two judgments of the Tribunal in their cases have not been challenged and have attained finality. The only question which falls for consideration in the appeal is whether the Tribunal was justified in denying to the appellant the benefit which has been extended to Harpal Singh, Sital Das and Jasvinder Singh in the earlier judgments of the Tribunal even though the appellant and the said officers were similarly situate and the appellant was actually senior to them in the cadre of Senior Computers. Having given the benefit of counting the period of their uninterrupted ad hoc service as Research Assistants for the purpose of seniority in the cadre of Research Assistants to Harpal Singh, Sital Das and Jasvinder Singh the Tribunal could not have denied the same benefit to the appellant and could not have treated the case of the appellant in a manner different from the cases of those officers. 8. The appeal is, therefore, allowed, the judgment of the Tribunal dated 5-11-1993 is set aside and OA No. 437 of 1989 filed by the appellant is disposed of with the direction that the period of uninterrupted ad hoc service of the appellant in the cadre of Research Assistants be counted for the purpose of his seniority in the cadre of Research Assistants as has been done a in the cases of Harpal Singh, Sital Das and Jasvinder Singh. No costs.