It applies to the payment of wages to persons employed in any:
Railways employed by a railway administration;
Railways, employed through a subcontractor;
Any other establishment.
The list is not exhaustive and Courts have extended the benefit of the Act under any other establishment by cases and more. Further, an appropriate government can after giving notice of its intention of 3 months in the Official Gazette extend the application of Act to any other class of workers. You can consult good employment lawyers in India to know if your case is covered by the Payment of Wages Act.