How can I deal with someone who is harassing me?

I caught a man urinating in my building outside the toilet a month back. Since then he has been finding ways to harass me. Initially there was no parking in front of my building, now he purposely parks bikes and his friends also do the same. He has placed plants right outside the building, and if i remove it he keeps it back. This is mental harassment. Last year he had broken the lock of the gutter twice to use it as a toilet to use it as a toilet by him and his friends. He has also built a structure illegally occupying atleast 3 foot of my building premises . He has placed a basin and a camera without my permission, also taken water connection from water pipe meant for my building. Under which IPC section will this complaint fall? Please suggest what should I do and what can be done.