Rent increase
New Jersey has no state cap on rent increases, but a landlord can't raise rent in the middle of a lease. They must end the current lease with proper written notice and offer a new one, and the increase can't be unconscionable, meaning shockingly unfair.
New Jersey example
Made-up numbers: your one-year lease ends August 31 in a town without rent control, and your landlord wants to raise rent from $1,800 to $1,950 ($150 more). They must give written notice ending the old lease and offering a new one at $1,950. To evict for nonpayment of the increase, they need a notice to quit served at least one month before filing, and a judge decides if it's unconscionable.
Official source
This is a plain-English summary. Rules and dollar amounts change, so check the official source or a professional before you file or sign anything.