As per the Provision of SECTION 49(5) of the Central Goods and Services Tax Act 2017 :
The amount of input tax credit available in the electronic credit ledger of the registered person on account of--
[a] INTEGRATED TAX shall first be utilised towards payment of integrated tax and the amount remaining, if any, may be utilised towards the payment of CENTRAL TAX and STATE TAX, or as the case may be, Union territory tax, in that order.
Hence, the ITC Balance of IGST can be utilized to pay :