4. Provisions of this Act not to apply in certain cases.-
During the period of operation of this Act, no relief shall be available under the provisions of section 3 in respect of the following encroachment or unauthorised development, namely:-
(a) encroachment on public land except in those cases which are covered under clauses 4[(a) and (c)] of sub-section (1) of section 3;
(b) removal of slums and Jhuggi-Jhompri dwellers, 5 unauthorised colonies or part thereof, village abadi area (including urban villages) and their extensions in accordance with the relevant policies approved by the Central Government for clearance of land required for specific public projects.