Property fraud

My grandfather bought a property long time ago that nobody knew about. Until my uncle found it and sold it claiming that he's the only surviving member of my family despite 5 of his siblings including my father's(father is deceased) family all living in same city. To the effect that he's the only surviving member my uncle and his entire family has signed a legal sale deed and received a DD from seller. The worst part is we live in the same building in a shared property they live in first floor and we on second. Me and my mom are alone. I wanna file a fraud case against his entire family and I want him arrested. Please help me.. 1.. how should I proceed ? Police or lawyer? 2.I want to file a civil as well as a criminal case against them. His family has tortured me and my mom our entire life and put us thru hell, after alot of struggle from a single mother I'm financially stable now. I would want revenge more than money. How should I make sure those maggots rot in jail? 3.Since my father is deceased what are the chances of winning my share of property, I'm the only child to my parents? Any advice is appreciated.