Does it come under cheating

Hi, land is in kerala , we had a tenant living there for 50 yrs. its our relative and our great granfather permitted them to stay there, at that time the house was also belong to great gandfather. we were paying land tax for entire extent of the property till date. we were not aware that they got any right on it. they were telling they got 'kudikidappu pattayam' for ten cent but were not showing any documents related to it. some politicians and other people in that area confirm they got pattayam , so I asked them to mark the boundaries of 10 cents as the govt gave to them. and they marked it. and asked me to show the pattayam to verify. but they were hiding it so I was wondering why they hiding it. recently I got the patta number and all its relevant documents through RTI, there was a sketch along with the pattayam , so they were hiding the sketch given by govt , not the pattayam. now the problem is , they marked the boundaries diffrent than pattayam. and police saying as I was there and agreed to mark the boundaries , its their boundary. actually they were hiding the document/sketch and they pointed out another area as true area. does it comes under criminal offense? they violated mutual trust of individual right? isn't cheating? Thank you, Sarath