Since he is in forcefull possesion of property, he only shall be liable.
File application in civil court where appeal in pending to restore you possession so that repair can be done as the property is in dilapidated condition and not conducive for human inheritance and live threat to neighbour also. Court may grant immediate recovery of possesion.
If he is denying your title, court may have evicted him at interim stage. You must be having some proof that he is tenant or rent receipt/payment etc ?