Legalized varisu tharar

Dear All, I wish that my query will be cleared. My Late grandfather and his Late brother made an mutual agrement in separate of lands by dividing a square land into four piece of land by cross method. This document is not available with us. My grandfathers eleder brother was married and had four daughters (only one alive rest of them died) in this elder daughter was married to his brother in law. While my grandfather elder brother before dying he transfered the land to his wife by issuing the power only. After both were decesed brother in law of my granfathers elder brother without sharing the land he himself registered the land on his name without canceling the power and at present he registered the total four pieces to his grand sons and at present these Grand sons are creating the problem that total land belongs to us becoz it is been registerd on there name and they kept the board that land belongs to them no trespassers allowed. My Late Grandfather was married and having a son (my father) now we filed a case with collecting the documents from the register offices and we are the one safeguarding the land by making the agriculture for several decades. In this situation our Lawyer provided suggestion to get the power from deceased elder grandfather daughter who his alive to run the case. We did the same. Case came to court on Dec 8th 2014 opposite party got Vaida for Jan 8th due to change in the lawyer. Within this period recently the grand sons of the opposite party came with other unknown persons and started measuring the land without informing us. So my father and my brothers asked the unknown persons who are you and who told to measure the land adjusant to the deceased land which belongs to us. We showed the court order, that this land under case and ongoing if anything we shall see in the court. But a lady was there in that unknown group and filed a FIR against my father and brothers in sec 509. Now we have filed Jamin and received the same. In this regards please advice how to move further.