hi my father bought a property in 1993 from a person and my father was a gp agent of the property he registered the property in 2009 now he sold the property to his friend some other person sends him a notice that the person who sold the property to my father in 1993 has given him a agreement in 1992.my father ignored the notice he tells me that any property which stays with us for 13 years will be ours we dont get a problem from the person who sent this notice and more over he has to send that notice to the person who sold this property to us.now what should we do please suggest a advice.