Rules for pagdi re development in dombivli, maharashtra

Our building is 30years old situated in dombivli east under pagdi system which comes under kalyan dombivili muncipal coorporation , wherein we didn't have any agreement kind of thing during the time we bought the pagdi flat. All the residents have first rent receipt in which the rate at which they bought flat is being mentioned on the back side. This is what we have as proof of pagdi system we bought. Now our pagdi building has received notice for dilapidated building and KDMC has told to do repair works. Now our landlord wants our pagdi building to go under redevelopement and against same one builder has approached us. My area under pagdi is 390Sq.feet. Builder is asking us to pay @4800rs. per square feet for our 350Sq. feet area which he is offering us where the current market rate of @8000rs. per square feet is rate going on in our area for new buildings. Now my question is that whether am I liable to get 390Sq. feet area without paying any single money , because same is the thing which i have heard is rule for BMC for redevelopment of the pagdi building. And if same rule isn't applied , then what is the rule for the same for KDMC. Also as we don't have agreement and he is telling that we won't get the accomodation charges till the building is not being built. Is this correct? Because as per him without agreement running pagdi system is illegal. Please help with your valuable answer.