Ancestral property issue

I wanted to discuss something with you regarding our ancestral property. We have two family homes—one where my grandfather's sister lives and the other where we live. However, despite us living in the house, my grandfather's sister has been running it as a rental property, and we’ve only been given one room to live in. Upon investigating the ownership details of both houses, we discovered that in 1976, the house was listed under my great-grandfather’s name in the municipal records. Later, in a 1986 general survey by the municipal corporation, my grandfather's sister added only her name to the records. No one in our family raised any objections at that time because everyone was poor and uneducated, and nobody knew much about property papers. My grandfather's sister never married, so technically the general survey itself was flawed, as it should have included all of my great-grandfather's children. Moreover, we have been living in this house from the beginning, and now we want to have my father’s name added to the municipal records based on the fact that he is the eldest son in the family. I don’t know much about the property papers, and I’m not aware of the khasra number or other important details. Is there anything I can do in this property matter? I do have water and electricity bills on my father's name, but they are from the year 2000 onwards. This is our ancestral property, and we have been living here from the beginning.