Patta vs registered document

I bought a property for which patta is having more 20 cent area and registered document is having lesser. The registrar disagreed to register the extra 20 cent so we registered only the area mentioned in registered document. The patta was issued on 1986, we went to the court and the seller claimed that for the past 31 years he is possessing this extra 20 cent and it is wrongly mentioned in the registered document and he would like to correct the registered document as in patta and give it to us. And so the court ordered the same and then we registered this order copy in the registration office. Now, both our registered document and patta is having the same measurement as the land. But the neighbor is claiming that he is having 20 cent less area and also his patta is having 20 cent less area but his registered document is having 20 cent more area and asking land from us. If we take this to court who will win htis 20 cent? My lawyer is saying we have correct measurement in all the documents and also as per adverse possession we have this extra 20 cent land for 31 years and we will win. Is that so?