The tenant is unreachable upon tenancy contract expiry. What to do?

Hi Legal teams,

I need your advice on my case. I am a landlord and my tenancy contract with the current tenant expired today (28th Feb’22). Since Dec 21, we were discussing the renewal over WhatsApp and the tenant was assuring us to renew the contract.

However, from last week, the tenant is neither reachable over phone nor email. He is not even replying to our renewal requests. Now, I have a tenant living in my property without an active contract.

What could be our best course of action in this case? Can WhatsApp chat be used in case of any dispute?

Can I raise a dispute with RERA for eviction in case the tenant is either still unreachable or does not sign the contract?

How long do I need to wait before I can seek a RERA dispute?

Thanks in advance!