Billing in case of sub contract operations

What is the nature of supply the subcontractor provide?

It is repairs /civil works sir.

This is a classic debate! The correct approach depends on the specific circumstances. However, generally speaking:

- If the sub-contractor is registered in Karnataka and the works contract is executed in Karnataka, it is considered an intra-state supply. - 

As per GST laws, intra-state supplies attract SGST and CGST. - Since the sub-contractor is not registered in Delhi (where the main contractor is registered), they cannot charge IGST.

 In this scenario, the sub-contractor should charge SGST and CGST to the main contractor, as the supply is within the same state (Karnataka).

However, if the main contractor has a registered office or a branch in Karnataka, and the sub-contractor is providing services to that office/branch, then IGST might be applicable. 

It's essential to consult a GST expert or chartered accountant to analyze the specific situation and ensure compliance with GST regulations.

Additionally,

 refer to the GST Act, Section 12(3), and the Place of Supply of Goods and Services Regulations for further clarification.