Gst annual return 9

1. Our client has paid CGST and SGST instead of IGST . So how to proceed in GSTR 9 . ?

2.Also option of DRC -03 is not available in Annual Return . so how to make payment for additional liabilities ? After activating button of '' Compute Liabilities '' also option of payment through DRC -03 is not available . So how to make payment ? 

Thank you