Uncle name as father

Dear Sir, I belong to Hindu family & 27 yr old . I have 3 Brothers & 2 sisters & I am the middle one. My fathers were two brothers and my biological father (Sh. Mahanandan sharma) is youngest one, means he had younger brother. The younger brother Sh. Satya Prakash sharma (My Uncle) he is my and one of my sister documents father. When I was around 6 yr I was admitted in the school at First Class. Later some time, I came to know that my Uncle’s name has been written at the column of father’s name in the school. I told this matter to my family and then they all told me that it has been decided by the whole family that one of the boy and girl is to be given the name of the Uncle (Mr Satya Prakash sharma) as father’s name. With mutual understanding. As ( Satya Prakash sharma) do not have any children. After I being the child & minor didn’t know whether it was right or wrong. Even in March 2009 Satya Prakash sharma and madhu sharma his wife get some misunderstanding and now they both not living together and he has done 2nd marriage in Feb 2010 without informing his first wife. Now he have his 2 children's from 2nd wife. at this time Satya Prakash sharma asking me and my sister to change father name to biological father as mahanandan sharma. I have my Uncle’s name (Mr. Satya Prakash sharma and madhu sharma ) as father and mother name in all my records like educational- Matric Certificate, 10+2, graduation , MBA and all others ID, DL, Aadhar Card, Pass Port & residential proofs etc. And also he telling that he will evict from all his and ancient property. At this age where I will go please guide me