patta title ownership - calrification

Mr A got agricultural land in the year 72 through Patta (No mother document) and same has been sold to Mr B and registered in the year 92 and that land has been bought by my mother (widow) in the year 93 with proper registration and taxes are paid till today from our end,( land located in Chennai Gummidipoondi) Now MR X ( unknown person) raised a complaint to Revenue department (RDO) conditional Patta land was sold illegally to my mother and RDO issued a letter to the registrar office to stop further sale transaction. NOte: current online Patta contains Ryotwari Patta and old manual patta contains given for monthly Kisthi but we are not sure really any condition attached to this patta or not. Also please note recently highway department taken over a few cents and compensation has been paid to my mother. Please advise on the below query How to handle Mr X claim? Is there any possibility for the government to take over this land if there is any condition added to the patta? This