Can we claim refund

If you paid more tax than required for the 2017-18 financial year, you can generally claim a refund. This is possible under Section 49(6) read with Section 54 of the relevant tax laws, provided the excess amount was paid via the cash ledger and hasn't been set off against other liabilities. You'll need to report the correct liability in your GSTR-9 and amend the tax paid column, keeping in mind there's a two-year time limit from the date of tax payment to file for a refund.