GST Explanation

If a member is a "Merchant Exporter" , the logic is:

If the state of their supporting unit has an office of CAPEXIL, then CGST and SGST is applicable, otherwise IGST. 

If a member is not a Merchant Exporter there won't be any supporting unit

if the State of Member's plant location has an office of CAPEXIL (e.g. If the Plant is in Maharashtra, and CAPEXIL office is there in Maharashtra, Mumbai), then SGST and CGST will be applicable. Otherwise, IGST.