Can A Unregistered release deed be enforcable in law after 10 yea

Hi, My family has ancestral land in which we are the 4th generation,the land has 4 main parts to it my grandfather passed away in 2005 and he had signed on a paper of 3.5rs stamp paper notarised by a notary (in 2004), along with all the other people whose name was on the 7/12 at that time to release their share in the land to one of the brothers son's(mr x) name whose name was also there on the 7/12 at that point of time. Mr X tried to remove everyones names from the 7/12 in 2006 and 2008 after my grandfather expired but his entried were rejected in the collectros office since the documentation was not registered thus incomplete. Thus none of their names (ie of my grandfather and the other people who were in the 7/12 prior to 2005 were not removed till date). Now Mr X has made an open claim to the plot fully as his whole , he doesnt have the kabza but he has given a notice in the papers saying he has taken the rights from the other members of the family in 2004 and now the plot is his,but the 7/12 has everryones name still. He is decideing to go to court, can we contest his claims ? the release deed was signed in 2004, now its 2014, it was on a 3.5 rs stamp paper notarised by a notary. My grandfather who they calim has signed has expired in 2005 only after which Mr x tried to get their name put by removing all other members names. will his claim have validity ? the collector has anyways cancelled his application twice to remove other family members names from the 7/12 .