How can I claim share in my grandparent's property

My grandfather has 4 child (2M 2F) my father was elder one unfortunately my father passed away before10 year we have only1 plot that was owed by my father himself we have no support of my grandparents after my father death we are suffering from money problem as we are alone. My uncle is converting all th property to his favour and my grandparents also are not ready to give us a single rupees so we need support if there is any law that can proves my rights and we can our legally rights Thank you