Pagdi system house claim

Hi, I am Manjiri Rangnekar a mumbai resident. We have a pagdi system house in Dadar which was owned by my grandmother. After she got ill, my uncle took over the house while my father continued to stay there with him. My uncle was married but has no children wherein my father had me and my elder brother. As the house was just 220 sq feet it was difficult to manage in that house. So father bought his own house in Kalyan and we all shifter there. My uncle continued to stay there with his wife. Few years ago my uncle died and our aunt got her name updated on the rental receipt for the house without informing us. Now she says we have no claim over the house. Since we don't stay there and will not give our share ever. However, my father was staying there for years and only to avoid family disputes had left the house. As a legal heir we wish to get 50% of share of the house. We are planning to file a legal case in court. But is it worth it?? My uncle had left a letter mentioning that my father stays with him and will continue to stay there..