Owner fighting for the 32 years old rented room

Respected Sir/Madam, My self Pratap residing at mumbai with my whole family including Mom, dad, younger brother & my wife in a 32 years old rented room. My father had deposited small amount To owner A. (which dose not have any deposit receipt) took this room on rent in 1984. Me, my elder sister & younger brother born in the same place. My dad had old rent receipt, Ration card, Election card on the same address since 1984. In 1993 year we had filed a case against the owner due to frequently & highly increasing rent. After few years we won the case & court had given a judgment to pay nominal rent. We were paying the same in court & later on through money order which agreed by owner in court. After few years. owner, her son, her daughter in law had passed away one by one & her grand son (Mr. B) was minor age (below 18 yrs). Hence some of there relative had taken his responsibilty & took him some where with them. We were not in contact since last 8-10 years as we didnt know his address & contact no. He have never taken care of our room, even not repaired any thing at our room. We have carried out 2-3 major repaires & lots of minor repairs in last 32 years. Now when grown up he have sold that property to some one else (C) without any intimation to us. This property is around 3000 sq ft & my room is of 250 sq feet carpet area. Now C is fighting with us to get this room empty. As C is saying he buy this propety & he have registerd power of attorny. We are still not sure that mr. B had realy sold this property or not? I want to know followings... 1) Can Mr. B sale this property including our 32 years old redident room without intimating us? Is this legally acceptable? If is not then what i have to do to? 2) can't we get ownership of the room atleast considering 32 years of tenancy? If it is possible what i need to do? May i know under which act tenants can get ownership in such cases 3) what i deserve to get from A or B ? (Room against Room or Money against room?) I have following documents with me pls. Consider & request you pls. Let me know which can be helpfull in my case as a evidence. *Ration card since 1984-1999 & revised new one from 2000- till date * Rent receipt & Money order slip since 1984 to 1995 * court Result & case paper (Rent control) * Adhar card, Election card, passport in same address. * Do not have water bill & Electric bill as it is on owners name. We have all electric bill since 1984 to till date which we was regularly paying. Humble request to all of you, pls. Guid & help us to come out of this.