How to acquire land which is under our possession for the past 32 year

Sir Myself is I am live in Jammu at garkhal Village. Sir my mother was bought a property from someone. But in One of man take a interest to get this property in inter change of his agricultural land . But he get gardouries ownership of said Land in his own name But deny to give the owner ship gardouries to us. and we are have the possess (kabza) of said Land from 32 years . Now he forcefully entering in our land. please tell me what we can do it