Hi
Since you have made an application through open direct recruitment examination and also after taking no objection certificate, you will have pay protection. Since ISRO comes under department of space, Central Civil Service Rules will be applicable and Office circulars issued by Department of Personnel and training will be the guiding factor.
Please refer to No. 28020/1/2010-Estt.(C), Government of India, Ministry of Personnel, Public Grievances & Pensions, (Department of Personnel & Training), North Block, New Delhi, Dated the 8 April , 2016
In cases of appointment of a Government servant to another post in Government on acceptance of technical resignation, the protection of pay is given in terms of the Ministry of Finance OM No. 3379-E.III (B)/65 dated the 17th June, 1965 read with provisions of FR 22- B. Past service rendered by such a Government servant is taken into account for reckoning of the minimum period for grant of annual increment in the new post/ service/ cadre in
Government under the provisions of FR 26 read with Rule 10 of CCS (RP) Rules, 2008. Pay of the substantive post held by the Government servant is protected. After Sixth Pay Commission, only the pay in the pay band is protected and the employee gets the grade pay of the post to which he is appointed after his resignation
As per the Ministry of Finance OM No. 3379-E.III (B)/65 dated the 17 thJune, 1965, the resignation is seated as a technical formality where a Government servant has applied through proper channel for a post in the same or some other Department, and is on selection, required to resign the previous post for administrative reasons. The
resignation will be treated as technical resignation if these conditions are met, even if the Government servant has not mentioned the word "Technical" while submitting his resignation. The benefit of past service, if otherwise admissible under rules, may be given in such cases.