Pagadi system house ownership

Hi... I have pagadi system house.still rent receipt comes on my grand father name. due to rent receipt come on my grand father name my cousin asking share . but this house is given by my grand father to my father. with family settlement but that time my father dint make any legal document on his name . it was oral settlement front of family member, everybody knows that house has been given to my father. since 40 year my father is paying rent to owner and our all document is on said premises ( Ration card Light bill, Adharcard, Voting Card) Light Bill and ration Card is on My mother name. because of house is pagadi system we enable to register on our name. after my uncle and my father demise suddenly my cousin stand for there share in said premises now they are troubling to my mother. since they know that premises all ready given to my dad. and they are not staying with us said premise over 40 year. even they don't have any residential proof on said premise. but now this property going on redevelopment they have submitted written objection affidavit to our chawl society . but all ready all document accepted on my mother name by mhada govt. but left over procedure still left by builder. What i can do in such situation which builder and society will not consider there objection . 3 year before we have took there NOC cum affidavit for our personal reason that time they gave us NOC and now they are denying WE have Notarize that NOC But Couldn't Make "register because our lawyer said chawl property cant be register. I hope good advise thanks and Regard Tanvi Kulkarni