How to get possession of my myadi patta land

can recover my myadi patta land from the possesion of others? They have been occupying the land for around 42 years. The land of total 12 bighas is located at Dadara gaon near Guwahati. our father died when we were minor at that time. so, taking this advantage they occupied our land. We many times asked them to return the land but they never agreed to return our our land. We have all the pattas, khajna rashid, jawanbandies etc. They even have not have rayati documents. In this circumstances, can we file a civil case suit in Guwahati High court against the occupants to recover the land? please suggest me what to do