My Rights in ancestral house as the only grandson

Hello My question is regarding my ancestral house in my home town. I am the only grandson of my grandfather who inherited this house from his grandfather. Below are the facts with regards to this property: - My grandfather died in 1999-2000 leaving this house to my family members. - My grandfather has three sons (all married) living in this house and four daughters ( all married but one divorced). none of them live in this house. - I am the only grandson of my grandfather but I have been told to leave the house as they do not have enough space for me. All the granddaughters have been married now and there are a total of 7 people living in this house. (My grand mother, My mother and father, my 2 uncles and 2 aunties). - I along with my wife and a young daughter were told by my father to leave the house and find my own living. So I left the house and currently working in Bangalore living in a rented apartment. - I dont know if there was a will that my grand father left but my father says that he has a will and that house has thus been divided by my grand father in three portions and 1/3rd portion that my father has received is unconstructed and not livable. Therefore, I would like to know my rights and how I can avail them with your kind help: - If I want to live in that house, do I have the right to do so? - I would like to use the ground floor of the house to open a shop that used to be there since my grand fathers time but now they have closed it. I would like to re-open it and work in it. - Can i access the copy of the will and find out if its legal or not?