Dear Saswata ji,
For your information and ready reference, I am providing the provisions under Section 1(5) of the Act as follows:
Section 1(5): The appropriate Government may, in consultation with the Corporation and, where the appropriate Government is a State Government, with the approval of the Central Government, after giving one month's notice of its intention by notification in the Official Gazette, extend the provisions of this Act or any of them to any other establishment or class of establishments, industrial, commercial, agricultural, or otherwise.