Registration deed vs re-survey deed

My father has a property in his name with registered deed executed in 1987. Later on he was of out of India for works. During 1993 a resurvey came in the area and the boundaries / sketch was drawn in such a way that the area assigned in the registered deed was not fully covered in the govt sketch. This was unaware to us we were not in india. Recently he has come to india in 2003 and he has settled here since then and paying property tax till today. Now due to some land disputes with his own brother's family; we have requested for re-survey from Taluk level. The resurvey based on our application was done and officer mentioned that though registration deed has more area mentioned in it but it is of no value and what is mentioned in the govt. survey sketch is final. My dad has been paying tax for the entire area as mentioned in the registration deed. Since we only have requested for resurvey and the proceeding was not in our favor and the officer also didn't consider the registration deed; we do not know what to do. As per officer's new pole stand position it will reduce our widdth of the way from 3 m to 2m approx. The land which has the boundary problem is also our only way to public road.The same property is the only way for relative to get into one of there second plot. Though the disputed land is owned by my father; officer is saying that we cannot make any boundary in this land as that will block the opposition party's way to their second plot and officer is of the opinion that though my father owns it, both parties can use it. Please advise what is to be done here now. Compromise is out of question as the opposition is not willing for it and they have good political, money influence and good hold in the survey dept. Hope you get some time to understand the issue and lead as the way forward now