Property Dispute

3 years ago

My grandfather married two times. 1st wife gave birth to 2 sons including my father. 1st wife died afterwards. My grandfather remarried again with 2nd wife now. She has no children. My father is from 1st grandmother who died before and my grandfather died afterwards. My 2nd grandmother is still alive. My father died after demise of my real grandfather and grandmother. Does my 2nd grandmother hold her share in my father property or not she is not her real mother?

How the property of my 2nd grandmother be divided as she don't have any biological child.

In my father's death certificate, my 2nd grandmother name is written and tehsildar is saying, he will go according to death certificate and he is saying your 2nd grandmother is eligible for one share from my father's self made property.
1. What is the procedure to change my 2nd grandmother name to my 1st grandmother in my father's death certificate as municipal corporation is saying that there is no legal proof/document with you which can prove my 1st grandmother as my father's real mother as my father was very small during her real mother death.
2. How to prove biologically in court that my father 2nd mother is a step mother?