Wrong demarkation

There were 3 bare adjacent plots (A,B, & C of 15’ x 60’ each) on same plot No. covering different khata Nos. Plot A & B is owned by owner X and Plot C was owned by owner Y. Y constructed a residential house in his name with all valid approvals like Town Planning, and Municipality. After completion of the house Municipality also allotted a holding number. Y is enjoying the property since two years. Now X came in search of his plot A & B and found that Y constructed house on plot A instead of plot C. Y was not aware of the fact until A pointed the same as he constructed the house after the same has been demarked by the competent authorities i.e. Aamin. As the house was alredy constructed, both the parties wanted to correct the documents legally by transferring plot C of Y to X and plot A of X to Y. While consulting with the advocates in our area they are giving different opinions which is not tallying with one another. Some say mutual agreement can be done between X & Y and the agreement can be notorized. Some say this is not legal and it requires registration of land C in favour X and land A in favour of Y. Some other say this is also not legal as there is a building over plot A so Y has to register only plot to X and X has to register both plot and building to Y. Some say this is also not legal as X is not the owner and not having any documents regarding the building. We want to file a joint petition before the court in this regard for rectification but some suggests that only in divorce case it is possible and in this case X has to file a suit against Y. The location of the plots is in Odisha. In this context I request you to please give your opinion how the same can be solved legally as we do not want any complications in future.