1. The rental agreement in the name of your father is not valid at this stage when your father has expired long back, the legal heirs cannot inherit the tenancy rights for more than 5 years especially if the legal heirs have been living in that property at the time of death of the deceased tenant.
The above will be applicable only if the property is not under pagdi system rental agreement.
2. The rental agreement cannot be renewed because of the nature of the situation.A fresh rental agreement can be entered into.
In Maharashtra any rental agreement varying any period may have to mandatorily registered by paying appropriate stamp duty.
If the legal heirs of the deceased landlord is not willing to enter into a fresh rental agreement then you may not be able to do anything except to vacate.
You can drag on the issue for some years if he is filing an eviction suit but ultimately the court may decide in favor of landlord's heirs only.
3. Pagdi tenants living in non-cessed buildings before June 13, 1996 are eligible for new flats whenever their building is redeveloped, according to new guidelines introduced by the BMC. Also, if a tenant has transferred the pagdi system flat in the name of another person after completing the required legal formalities, the new occupant will have equal rights and will be eligible to get accommodation after redevelopment.
Hope yours is not a pagdi system tenant?
4. You may not have any rights especially the tenancy rights in the absence of effective rental agreement, this is legal position.