Input tax credit.....?

we are the traders of cement and iron and also we provide labour on demand and we collect 18% tax on respective service.

we have obtained single registration eventhough they are two business verticals with in same state.

so we need to file gstr-1 and 3b for both businesses combinely as we have in registration only.

so my question is , can i claim the input tax on cement and iron aginst the output tax of labour supply.

please mention respective sections and rules

thank you