Chances of winning a challenge on family compromise agreement

Hello sir/madam my grandparents have 5 sons and 1 daughter, eldest son being my father . Unfortunately I lost my father in 2008 . Later on it was only me and my mother in our family. So after my mother pestering my uncles to divide the ancestral property they agreed and came up with a will which was done by my grandmother before she died. According to the will, everyone gets 1 acre land each except the 3rd son who got 2 acre land. And the daughter gets a site and a house which is more worth than all . Everything looked ok to me and my mother as the land that was for us had pahani . Hence we signed the compromise final decree at the court. Later we realised that the inside documents of land given to us had serious problems, like the survey documents such as akarbandh and tippani states it as Karab land whereas the lands given to my uncles have clear documents and are easily saleable. So is it possible to challenge the compromise agreement we signed on the grounds that the land we received in the partition is not an ancestral land but a government land . And can we ask court to redistribute the land as my 3rd uncle has got 2 acres ??