Section 3(1)(a) in The Tamil Nadu Buildings (Lease and Rent Control) Act, 1960
(a)(i)Every landlord shall, within seven days after the building becomes vacant,-(A)by his ceasing to occupy it, or(B)by the termination of tenancy, or(C)by the eviction of the tenant, or(D)where any such building has been requisitioned under any law for the time being in force other than this Act, by release from such requisition, give notice of the vacancy in writing to the officer authorised in that behalf by the Government.(ii)Every tenant shall, within seven days after the building becomes vacant, by his ceasing to occupy it or by the termination of his tenancy, give notice of the vacancy in writing to the officer authorized in that behalf by the Government.