Section 16(1) in The U.P. Urban Buildings (Regulation of Letting, Rent and Eviction) Act, 1972
(1)Subject to the provisions of this Act, the District Magistrate may Allotment and by order-(a)require the landlord o let any building which is or has, fallen vacant or is about to fall vacant, or a part of such building but not appurtenant land alone, to any person specified in the order (to be called an allotment order) ; or(b)release the whole or any part of such building, or any land appurtenant therein, in favour of the landlord (to be called a release order).