Udr patta cancellation after 30 years

My uncle bought a property from a person in 2015 based on some patta which they have and received patta on his name. later he came to know some problem due to their co brothers related to land . so he gave back to the person in the mean while he died unexpectedly before getting money. so later they register to my name with my aunt willingness and obtained patta in 2018. later in 2018 i sold the property to another person and obtained his patta. now we received a RDO letter stating that the patta issued in 1985 to the person who is father of the person who gave the property to us stating that his father had occupied near by land aswell. But till 2011 they paid the tax for the whole land and received government funds for the agri land as farmer. after issuing UDR patta in 1985, first registration for the land happened in 2014. later in 2015.again in 2018.all transfers includes patta transfer aswell. so i need some clarity whether the case filed person have right to claim after these many years of poseession land and cancel all these recent patta transfers.