Foreign purchases in gst returns

Just leave it for now, treat it as expense while filing IT returns.

AFAIK there is no Input tax credit for purchases from outside the country anyway. So why complicate an already complicated system? 

Is the IGST is on the duty alone? or the whole amount? How can they charge IGST for purchases outside the country... 

Thanks.

IGST is charged on the assessable value.

Assessable Value = Value of goods + BCD (Basic Customs Duty)

Eg. If the value of goods in Rs. 1000/-, and BCD is 10%, then the Assesable value becomes Rs. 1100/-

If the IGST for that rated value is 5%, then the total IGST amount becomes Rs. 55/-.

Total amount that goes to the government is Rs. 100 (BCD) + Rs. 55 (IGST) of which the IGST can be claimed for inputs.