Property Issue

We have a land in GOLLAPUDI,VIJAYAWADA. It was an unregistered plot bought on 2008( 1080 sq yrds). There have been a couple of people who recently have come and claimed that they have also purchased that land. One doc is 2003( 200 Sq yrds) and the other 2019( 300 x 4=1200 sq yards). We had filed an FIR with the local station and the CI has asked us to get a Mandal Survey done. The 2019 person who applied for the survey called and said that the surveyor called and said there were totally 42 buyers in that S No(4.9 acres) and he has to write letters to all to get it started. He was suggesting the CONS of this survey is 1) TIme 2) Possibility of more claimants 3) Long legal battle after the survey between us. Instead he has suggested we 3 come to an agreement and get a buyer to dispose of. I have the following questions: 1) How long will such surveys take 2) Is he worried that the survey will prove them wrong 3) Can they go to court even if the Survey proves they are wrong 4) H