Somebody is trying to steal my site

Hi Ajay, We own a site in bangalore for about 5 years and we have a registered sale deed, khata and have been paying tax regularly. This land was an agricultural land owned by A, which was converted to residential layout by a housing society by giving GPA to B (from that housing society). This happened about 20 years ago. Our site and a few surrounding sites have been vacant, in fact is still vacant. Now, some random builder X is stating that they have purchased the entire agricultural land from the sons of the original owner A (who is no more), and so have filed a declaration suit and got a temporary injunction against the current site owners (about 10 people). Company X openly claims that there was a loophole in the GPA, which is that B was given powers to convert the agricultural land to residential plots and do everything necessary for that. But the fact that he could further sell it was not articulated in the GPA. So company X has gone ahead and purchased the land and got a new registered sale deed for the entire agricultural land. We have all the sale deeds from housing society to the first buyer and the subsequent buyers, intact. This is definitely somebody taking advantage to acquire a vacant piece of land to go ahead and come up with their apartment or whatever and make money. Here are few important points: My plot is not mentioned in company X's case file, although company X's sale deed refers to the same piece of agricultural land that is mentioned in our sale deed's history. But when we tried to clean up our site, their attorney approached us stating that they have got injunction on the land and so we would have to implede ourselves into the case. How should I deal with this scenario and ensure my site stays with me? NOTE: This X builder is obviously powerful and has got influences