Third Party Registration Form

We only use Payables, Fixed Assets and GL for our India Org. We just get supplier services. We only have TDS regime

Here is our question

• We would have supplier with sites by state. We would like to store GST number by state for each supplier site using third party registration form. Current form defaults based on NULL site. This would not allow us to store separate GST #
• Do we have documentations which details how GST tax functionality would work for organization who does not use Purchasing, Item Inventory, Items, Real Inventory Org etc.