Tenancy Rights in Pagri System

Hello, I am resident of Mumbai Suburb with rental house in old pagdi system. We have received notice from BMC for evacuation of building as the same is in dilapidated.(354) Landlord is not accepting rent since 2012. Landlord is saying we need to enter into agreement and consent letter for redevelopment, which will protect our tenancy rights even if building collapses.Same agreement has clauses for redevelopment without any plan & timeline.He is offering us same carpet area with ownership. No alternate accomodation or rent till he receives IOD. The agreement would be notarized and not registered. Need reply for following queries & section they are covered under: 1)If we do not enter into agreement & building collapses,do we lose our tenancy rights? 2)Is there a minimum area to be given under redevelopment in suburb area? 3)Can there be a time bound agreement wherein landlord has to start redevelopment process? 4)What happens if I do not enter the agreement? 5)What options are available fo us as tenants?