Dvat on closing stock

i am auditing on a tea company DDPL (kolkata), tea are sold to ultimate party through auction or consignment sale. While selling goods on consignment sale the purchaser get form F for this selling company and not consignee.

In this case it is ultimate sale and not stock transfer but then why the purchaser get Form F for selling company from sales tax department ?

if this is because tea is exempted from sales tax?