Now that he has indicated in the Caveat Application that "caveat schedule mention property is absolutely belongs to the caveator only and the same in his peaceful possession and enjoyment of same since 1986 on wards without interference of any one in the locality till to this date", all of you should know that he is claiming it to be his absolute property.
Having come to know his claim, if you feel that what he says is wrong then you have to take appropriate legal action by filing suit. If you do not do now, then it will be presumed that what he has said in the caveat application is correct.
Therefore, you have to approach a local lawyer well versed in property law, show all the documents in your hand, discuss the detailed facts and then take appropriate action without wasting time.