How to claim ancestoral property

Hi, this is Gotham and I'm 26 years old. Actually, my grandfather had a huge property in Chennai city. But after the death of my grandfather, the list of properties he had, also vanished. And the list of properties is only known to my uncles (two sons of my grandfather). And they both claimed all the property by themselves and didn't give a single penny to their three sisters (that includes my mom). It is assumed that my grandfather had two bunglows in the city and acres of agricultural land. The two brothers (my uncles) they claimed each bungalow and are residing in it. And the acers of agricultural land, they set up an drama stating that the neighbour land Lord is trying to occupy their land illegally. So they need power of attorney to fight the case. Having the trust on their words, my mom signed on the notary blindly and my dad also blindly signed as witness. Few years later it was found that the notary which was signed by mother was for willingness to sell the agricultural land. And they had sold that land without the knowledge of their sisters and ate up all the share. When this all happened, my mom was totally upset but still she didn't want to file the case against them. But I want to file the case against them. So someone pls guide me so as to claim the ancestoral property and teach them (my uncles) a good lesson.