if you have claimed ITC wrongly then reverse it through Form DRC-03 before filing of GSTR-9 with interest of 24% per annum. For the amount of wrong ITC, you can use your credit ledger, but for 24% interest you must have to pay through your bank account.
1 hope is here you can try many more try including me ..
if you pay excess laibility in 17-18 (not claiming ITC) I m taking about output laibily shown excess then you file your gstr 9 in correct value . after it fiLE RFD-01 (EXCESS PAYMENT OF TAX ) and attach your relevant doc