Section 47(2)(a) in The Delhi Rent Control Act, 1958
(a)the landlord shall, within seven days of the premises becoming vacant, give intimation thereof in writing to the [Director of Estates] [Substituted by Act 58 of 1960, section 3 and Sch II, for "Estate Officer to the Government of India" (w.e.f. 26-12-1960).]