You may apply for advance ruling. The ruling passed on your application will bind on you. If you follow any other ruling to back your contention then that may fail. In Pre-GST regime, there was similar issues which concerned many was that free issue supplies given by the recipient of supply to the contractor to use those goods in the execution of the works contract service. There is no connection of that case to this query. But only to give an example that if a provision is there in the Act, it has a weightage and authority has to follow the same. That is to say, if section 17(5) restricts the credit claim of construction material and service, then that will be disallowed by the authority.