Pagdi rent receipt not in the name

Dear Respected Members, I seek for your help for below subject. Me and my family (3 generations:me, father, grandfather) have been living in a pagdi system room for last 40+ years in Central Mumbai. However the rent receipt is on the name of my grandfathers brother and the house was being given by him to my grandfather in mutual understanding. Both of them have passed away now. However, no paperwork was done and the rent receipt and electricity bill is still on my grandfathers brother's name. The brother has 3 sons and 2 daughters (related as cousins to my father) out of which only the two sisters are alive. We have below documents on our name Passport Aadhar card Voting ID Gas bill Domicile certificate The landlord is refusing for transferring the rent receipt name. Also, my fathers cousins have seen an opportunity to take share in the money and as such have refused to sign any NOC. The building is in a very terrible condition such that it is not possible to continue living there. In this case we want to lock it away and live elsewhere on rent. However this would end our occupation/possession. Also, in case of redevelopment what chances do we have of getting on our name. Kindly advise what would be the best course of action. Regards,