how can i get my grandfather's property back he died in 2001 ?

My mother's father had several properties including agricultural and commercial both. my mother was the single child of the family. my grandfather passed away in 2001, then my mother's relatives threatened my mother and father to leave all the property so that they can grab it all. none of the family member of ours tried to claim the property of my grandfather. As now my mother passed away in 2016, October 20. now I, her daughter, 19 years old want to claim my grandfather's property. there are total three members in my family, my younger brother,17 years old and my father. so how can anyone of us claim the property.