My father has 3 brothers and 5 sisters, in that my father is elder than others, my father's father h

My father has 3 brothers and 5 sisters, in that my father is elder than others, my father's father had took money and that money being paid by my father none of the other 3 brothers, and all the three totally dependent on my father, my father made her all the sisters to get married, three brothers after well settled they refused to pay the amount even upon the request now what my? Is how to get money from them legally, in that 3 one is senior lawyer. How do I handle the case, further?