Tenant Rights under Pagdi System

My father (previously by my grandfather) is a tenant under the Pagdi system in Mumbai for more than 75 years. Our shop & home got demolished under the road widening scheme by the Municipal Corporation of Mumbai in 2017. Half of the area was taken away and the other half remained. Where we rebuilt the shop within the rules and guidance from BMC. The landlord was not in touch during that time and for the past 30 years. He never came to collect rent. But after this latest development, his son has come back to action. He is claiming the property as he alleges that we unlawfully modified the original structure. The case is in court. The landlord's lawyer claims that under Sec 15(1) of the Maharashtra Rent Control Act, 1999, the tenant is not ready and willing to pay the rent. So in return, my lawyer is suggesting a draft where he is mentioning that we are always willing to pay the rent for the unpaid period in court and will continue to do so every month by depositing the rent in court until the proceeding is going on. My QUESTION is... should we first not question the landlord for being mysteriously unavailable for 30 years. Also, if we do agree to pay the rent till the legal proceedings are going on... What happens after that? My concern is right now we will be paying rent at a very cheap price under the Pagdi system. But going forward if the landlord renews the agreement and then starts charging us more rent, which could easily shoot up 200 times the actual rent we are paying. Then what do we do? Because we won't be able to afford it. And in that scenario, he will ask us to vacate. What are the rights of tenants on such property and will this be considered as a redevelopment, giving us the ownership rights of the shops? Please share your valuable advice.