Can landlord increase rent without 90 days' notice?

Hi,

Our agent has asked for a rental increase without giving us 90 days' notice. He has only given us one month's notice.

He is now threatening us that if we do not agree to the increase, he will ask for a Rental Valuation Certificate, and the increase will be much higher.

My question is, can he do this? RERA states that he needs to give us 90 days' notice.

I have looked at our contract, and even though it does not explicitly say that he needs to give us 90 days' notice, it does state that the increase will be according to RERA guidelines.

I would really appreciate your help with this matter, as we are feeling very stressed at the moment.