Uncles not supporting to clear ancestral property issue what to do

My father was died. We have property of my grandfather still not shared. My father have 2brothers&1 sister. My father was elder. First bro did job with fake certificates like "son of another's grandfather instead of own" . He was also died, his son doing that job now. Second brother saying that he is not eligible for our property, not accepting to share with him. My aunt(first brother's wife) saying that we are eligible, want equal share in all properties. They are settled well in different places. We are staying in rented house. my mother& bro doing business at footpath. I have sister, cames to marriage stage. Present we don't have any land or own house. My uncle & aunt not supporting us in this property issue. How can I file case against them?