My grand father cheated my father

Hello iam from Andhra pradesh.My grand father has 4 sons and 2 daugthers.. My grand mother died 22 years ago.. my father is the first son of my grand father.and we are 3 sons to my father. my grand father earned some good property with the help of his sons by doing business and agriculture. He earned 20 acers of land and also business and he kept secretly alot of liquid cash. 4 years back my grand father shared his property by the absence of we. He just gave a 2 acers of land and one old house (which is more then 20 years old) to my father. and he constructed new houses to his remaining sons. he secretly shared the total business and cash to his remaing sons.what should we do now? is there any law to get equal property to my father.pls help us. and my father and mother are uneducated. remaining all of them are educated. and one thing we 3 are only grand sons to my grand there any law to take legal action on my grand father. Iam 24 years old. and one thing my grand father have some power with the support of mla and some polices. pls give your answers.