If the Controller, after giving the tenant a reasonable opportunity of showing cause against the applicant, is satisfied (i). . . (ii) that the tenant has after the commencement of this Act without the written consent of the landlord (a). . . (b) used the building or rented land for a purpose other than that for which it was leased, or (iii) that the tenant has committed such acts as are likely to impair materially the value or utility of the building or rented land, or xxx XXK xxx (3) (a) A landlord may apply to the controller for an order directing the tenant to put the landlord in possession (i) in the case of a residential building if (a) he requires it for his own occupation; (b) he is not occupying an other residential building, in the urban area concerned; and xxx xxx xxx (i a) in the case of a residential building, if the landlord is a member of the armed forces of the Union of India and requires it for the occupation of his family and if he produces a certificate of the prescribed authority, referred to in section 7 of the , that he is serving under 166 special conditions within the meaning of section 3 of that Act.