Joint family property issue

2 years ago

We are Jain (minority) family. We have 2 BHK ownership flat in a society in western subarb of mumbai. Originally property was in joint name of my grandmother and my father. While purchasing property , my father had contributed 50% and my grandfather had contributed rest. Now my grandmother is expired. I had 2 uncles & both have died. My cousin sisters (daughters of one uncle) are still staying in that property. Presently society is issuing maintenance bill in name of my grandmother only and paid by my cousin sisters only. Now society is planning for redevelopment as it is 45 year old building. My other uncle has 2 son. So in 50% share of my grandmother , my father + 2 cousin sister + 2 cousin brother has share being legal heirs. Incase of redevelopment , how we should make agreement with builder. If we 2 party wants to sell flat but If My cousin sisters do not agree to vacant flat inspite builder is ready to give them their eligible share , what to do ? If my cousin sisters do not agree to sell flat , what is solution.