Hello Jab! You'll need to contact they city's rent control/rent registry department and register yourself as a new owner and reset the rents that were established by the previous owner. You can set your own rents only when and if you contact the city and file properly.
If you have any other questions please don't hesitate to reach me.
Best of luck!
RE/MAX Gold Coast Realty
56 Newark Street
Hoboken, NJ 07030