Division of property

My query is that we are three sisters and my mother and father expired 3 years ago.my father left with no will and so much of constructed as well as commercial land with no construction.out of every constructed property he gifted a house to one of my sister and before he could write a will or gift other things to both of us(me and my elder sister) he expired with no will.now when I and my elder sister ask for division or consult any government official regarding distibrution of the same.my sister who has got the house goes there and threatens the officials not to provide us any document regarding the property.both of my sisters are married and the one who has got the house has got a baby too. I am unmarried and the elder sister has done intercaste marriage so they (relatives and middle sister and her husband) say that she is not eligible to claim right in her share.My father never denied for her share plus both of them got married infront of my father.2nd sister and her husband also threatens us if we anyway try to ask them for division. now my queries are- What should I do to get my and ny elder sister’s share? What is the legal procedure for the same??