In this case on goods purchase and sales, IGST will be charged.
Sales Amount Outside State 100000
Purchase Amount Outside State 120000
- CGST 9%
- SGST 9%
Calculate GST Payable
Since Goods are sold Outside State,IGST will be charged
Rate of IGST=CGST+SGST=9%+9%=18%
Since IGST Input is More than IGST Output , it is IGST Credit.