Change of date of birth at 50 age

Please advise me the possibility and procedure to change (lower) my DOB from recorded 20.3.1966 to actual 20.3.1969. While joining school, the HM of elementary school changed my DOB to meet minimum age for SSC Exams. I born in a rural village in Telangana and presently working in public sector in Andhra Pradesh. Now i want to get my DOB corrected as that 3 years additional service will be vital for my family particularly to my 6 years old kids. All my records are with recorded age. My father noted my Dob in his 1969 dairy on the actual birth day but the same is not available now. But he recorded the DOBs of all my elder brothers in his 2006 dairy and also in a note book which are the only proofs available. My birth was at home and still not obtained any birth certificate from gram panchayat. My father is no more. One more proof is DOB (actual as well as recorded on SSC certificate) of my elder brother as 27.1.1966 which just 2 month older to my recorded DOB. I also learned that there is a direction from Apex court that request for DOB change at retirement stage is not considerable. Is it correct? Please suggest me to which state court i have to approach and the procedure and possibility.