(1) x x x x (2) Notwithstanding such repeal X X X (rr) where any permission referred to in section 3 of the 566 old Act has been obtained on any ground speci fied in subsection (1) or sub section (2) of section 21, and has become final, either before the commencement of this Act, or in accordance with the provisions of this sub section, after the commencement of this Act, whether or not a suit for the eviction of the tenant has been instituted, the landlord may apply to the prescribed authority for his eviction under section 21, and thereupon the prescribed authority shall order the eviction of the tenant from the building under tenancy, and it shall not be necessary for the pre scribed authority to satisfy itself afresh as to the existence of any ground as aforesaid, and such order shall be final and shall not be open to appeal under section 22".