My mother has 5 brothers and 1 sister. Her father has died and left property(land) Her father had al

My mother has 5 brothers and 1 sister. Her father has died and left property(land) Her father had also 2 brother. So property was divided in to two parts. One share was of her father and one was for her uncle.Her uncle had no sons and no daughters. Her uncle also died .My maternal uncle took thumb impression of the wife of my mother's uncle on a will at the time of her death. .The will gave property to my maternal uncle's sons and daughters .In Will my mother and other sisters were excluded. My maternal uncles have refused to give share to my mother and other sisters in ancestral property. My maternal uncle are selling the property both of their father and their uncle and building big houses, purchasing costly cars but their sisters are poor. Can we claim on property of my maternal grandfather and on the will which excluded sisters? And what about the property that has been already sold by my mother's brothers.