Query related to property in Mumbai

I have a property which is registered on my mother and father's name jointly. My father passed away in 2014. In that property we are now 4 people living out of which 1 is an unmarried woman who happens to be my father's sister. The house was on landlord ship before redevelopment and was on my grandfather's name. After my grandfather's death (in 1993) my father took care of all the expenses and maintenance of the house. My father has total 5 sisters out of which 4 are married. The house went for redevelopment in 2007 and we received the possession in 2010 and since possession of redeveloped house the agreement has been on both my parent's name jointly. We are planning to depart (my mother, brother and myself from my aunt) due to years of internal conflicts. My mother is the only earning member of the family and has been taking care of the house with maintenance and expenses ever since my father passed away. Whereas the aunty earns her own set of money for her personal expenses. I want a solution where I don't have to lose/sell my property just because she has been living with us for a long time. Is there anything that my aunt can claim for a share, since the house was not on ownership basis at the time of my grandfather's death? If so how much are we liable to pay her for her to leave the house?