Issue with residential poperty

We're facing quite an extraordinary situation within our family. Initially, my father resided in a joint family setup after marrying, where unfortunately, his brothers exhibited violent behavior towards the female members, including my mother, and among themselves. When my mother, pregnant with my sister, found the abusive environment unbearable, she made the decision to leave the joint family household. My father, supporting her, opted to move out as well, and they began living in a rented accommodation for several years. Financial struggles were prevalent initially, but stability eventually came. My grandmother, seeing the importance of my father having his own home, persuaded him to construct a house on an empty plot owned by my uncle. With my uncle's consent, my father erected two floors, diligently repaying all associated loans. For the past 25 years, we've resided on the first floor, bearing the responsibility of maintaining the entire property. Meanwhile, the ground floor was rented out, and rent was collected by my uncle, yet no contribution was made towards upkeep. Three years ago, my uncle passed away without any children, leading to the property being transferred to my aunt's name. Presently, she, along with other uncles, is pressuring us to sell the house. Despite my father being the sole builder of the entire house, legal documentation does not reflect his ownership. However, our residency for over 25 years, along with utility bills and other administrative documents under my father's name, serve as substantial evidence of our long-standing presence and contribution to the property. Considering the situation, we're exploring potential legal avenues to address the matter, having attempted negotiations with my aunt, who remains unwilling to consider selling the property. It's clear we've reached an impasse, but we hold onto hope that there may be a legal remedy to safeguard our interests in the property.