How to change names legally in town survey record and get patta by correcting the fake name

Hi Sir/Madam, In the year 1985, my grandmother (my mother's mother) got the land (porambokke) which is a unregistered document. She has been paying taxes from the year (1985-2003). My grandfather has an affair and got third marriage, because of this issue my grandmother and four daughters told him to getout from the house. He got angry and beat all his 4 daughters and his wife(my grandmother), he took the property documents and left the house in the year 2002. Grandfather started to change his name in EB and property tax. My grandmother came to know this and she gave gift settlement deed to her 4 daughters in 2003 and got encumbrance certificate for that gift settlement deed. By somehow, my grandfather created a fake unregistered document on 1982 and also has got his name on town survey record, then he started filing the case against my grandmother in the year 2003 saying it was his land , also he got manual patta in his name. But in 2017, court has fined 1000rs for filing case against porambokke land and court has mentioned whoever is staying in the land will be the owner. In 2021, we have changed the property tax and EB from his name to 4 daughters by using gift settlement deed given by my grandmother. He came to know that we have changed his name in property tax and EB, so he filed a police complaint. I need to know how to correct the name in Town survey record and get cancel his manual patta. We already have sent registered post to tahsildar in RTI act. But no response has been received. How to proceed this case further and change the town survey record name to 4 daughters name? Thanks in advance. Please help this case