Will daughter have share in father property

1.a flat is in the joint name of my father and mother. He has 6 daughters and one son. All are married. 2.. I am eldest daughter. He made me nominee which was duly submitted to society and acknowledged by society in 1999. So i am deemed member. 3.. My father died in 1999. He has not left any will. I have 5 married sisters and one married brother. 4. I want to know : a) are my 5 married sisters and brother also eligible for share? B) as i am deemed member, is it necessary to submit affidavit and undertaking of no objection to transfer in my single name from my 5 sisters?