Tresspass property in bangalore

Sir, We have a site60x40 in BBMP limit with constructed small 10x12 temporary shed with power connection registered and having B katha in my mother name, recently the person beside the site approached us many times to sell the plot we refused later he broke the room lock and taken the possession also started parking his car in the vacant site,when we approached him he says the site belongs to him and threatening to kill regarding the same we filed the tress pass complaint in Police station with all documents , police suggested us to file the PCR in court to prove the ownership of the plot. I am asking what PCR and it was the right decision by local police to suggest us to approach the court after producing all the necessary documents also he doesn't hold any documents. What way I go ahead please suggest. Thank you