Landlord increased rent without notice, can I refuse to pay in Delhi?

I've been renting a flat in Delhi for over two years. Last month, my landlord suddenly increased the rent by ₹5,000 without any prior notice or discussion. This increase was mentioned in the rent agreement. Now he's threatening to evict me if I don't pay. Is this legal? Can a landlord increase rent without any formal notice? What are my rights as a tenant in this case?