Higher education consideration

Hi sir, when I was working in DRDO I took permission (NOC) for higher studies and during that time I applied to ISRO through proper channel (with NOC) and application filling time I mentioned that I am pursuing my higher studies, ISRO delayed 3.5 years to application process and that time my higher education completed and I submitted my certificates to DRDO for updated this in my service book, later I got job in ISRO and during relieving from DRDO they relieved me in technical formalities and when I took up new job in ISRO I submitted my certificates, I informed to admin that I completed my higher studies during my service and everything mentioned in my previous job service book (when I joined Diploma and When completed my Diploma), so now my question is whether I am eligible for special review (department exam) or not, because my previous service, leaves, LTC, pay protection everything counted in my new job (ISRO). Moreover both companies belongs to pure Central Government and both are research organisation, so please help with right answer and what rules applies for this.