Bmrda approved layout - bangalore - dispute

Hi, I am from Bangalore and I purchased a BMRDA approved layout in Bangalore in 2011. I have taken loan from LIC housing finanace and have finished the loan recently. I got the E-Khatha and i am paying the property tax every year. When i got my sale deed registered i got an affidavit signed by the GPA holder stating that if in case of any litigation he will clear it on his own. I am about to construct house in my plot. Now recently few people have put civil case on the GPA holder who has sold this property to us, stating that he needs to pay money to them. The GPA holder had purchased the land from a family and some of the family members have put the case against him and they have painted out layout with the OS number and have put a board with the OS number by coming inside the layout. The builder is not caring about the case and he is not appearing for the sessions. So we residents are worried and talked to the GPA holder, he say that he will take care and get the "injection order" and get the board removed but he is not doing anything. 1. Can we move to court putting "cheating case" on him and based on the affidavit that he has signed, asking him to clear the litigation. 2. For the existing case, he is not appearing in the Civil court for any of the sessions, so will the judge declare judgement in favour of the other party who has put the case? If yes, then we will have to suffer. We are unable to sell the property. This is belonging to Bangalore anekal area.