Section 30(2) in The Inter-State Migrant Workmen (Regulation Of Employment And Conditions Of Service) Act, 1979
(2)Nothing contained in this Act shall be construed as precluding any inter-State migrant workmen from entering into an agreement with the principal employer or the contractor, as the case may be, for granting them rights or privileges in respect of any matter which are more favourable to them than those to which they would be entitled under this Act.
