Can We Claim Our Property Which Was Sold 18 Year Ago By Our Cousin Grandfather

We have ancestral property in Dehradun, we already had 2 level of partition done on our agriculture lands. One with our grandfather level, then with father level. Around 3-4 year back we found that one of 'Cousin' Grandfather (who is still alive) sold our portion of land in 2003. We have Kure created on sajra (which are certified copy of partition done between grandfathers in 1992) where its clearly mentioned that he sold our portion of land. On ground level also we have less and opponent has more. Can we file a law suit to claim our share of land which he sold 18 years ago? we came to know about it recently only when we saw old partition.