Landlord can increase only when the current contract ends.
In a new contract or contract renewal , he has the right to increase rent.
If you dont agree, you have to leave the premises.
If you dont leave the premises, he cant bring people and take you out by force. if he did that , you can call Police. He has to approach court and file case against you and he will win and end you have to leave.

Recommendation: If contract period has ended, then better move if you cant afford rent and dont get into cases etc and waste your time n efforts.