How to get official rights on Grandfather's(dead) property

Sir, We are two sisters, both are unmarried, 27+ & 25+ years aged. my father was only son (no daughters or brothers) to my grandfather. we are only two daughters (no sons) to my father. my grandfather was dead in 2005. my grandmother was also dead in 2006. my grandfather has some land in his name. I don't know whether the property was mutated or ancestral property or self acquired by my grandfather. Now my father is enjoying the property, and he is not caring us since our childhood. my mother, sister and me are living together and far away from my father since my childhood. My father is a psycho, left us, and enjoying the property alone. How can I & my sister get full rights on property? Is there any possibility to get property without my father's cooperation and sign? and what is the method that we follow like "mutation/succession/registration" for getting full rights on property and how to do the process? Who have the full rights or more rights on said property whether we or my father? Can my father sale the property without our cooperation, or can we sale the property without my father's cooperation? please give us your contact number.