Replacing Foster Parents Name To Biological Parents Name

Dear Sir, Greetings, I am in urgent need of help. Please advise what should I do. When I was 6 months old, my mother died because of a disease and my father did second marriage to another women. Also, my maternal side family believed it was because of carelessness of my father and two family hated each other. Because of this dispute my maternal grand father and grand mother took me and raised me as a foster parent and given their names as they believed my step mother will ruin my life. They put their name as my parent because in school or everywhere you need parents proofs to get admission. But they are not my biological parents. But now I want my biological parents name on my documents (Adhar, Pan, Passport, Certificates, etc ) so that I can prove my citizenship, etc in case of NRC and also I want to claim my biological father's property. I searched for gazzette but that is valid only for self name change but not in case of parents. I approached some lawyers and they are telling me that it will invalidate my all certificates and it will be of no use. Should I file a civil suit order or declaration in Civil Court to get my biological parents name or anything else? Will my all certificates will become invalid if I change my parents name to biological parents name? What is best method to get my biological parents name on all my documents that too legally that can be valid all over world. Please, I beg for help. Please help. I am also ready to pay the fee.