If you are having or dealing multi currency it will show unadjusted forex gain/ loss.
Follow this link to solve the problem https://tallygame.com/tally-erp-9/tally-advanced/multi-currency/how-to-use-multi-currency-forex-voucher-entry-in-tally-erp-9/
Review the entries: Go to Display → Account Books → Ledger → Forex Gain/Loss and drill down to see which transactions are contributing to the balance.
Correct the vouchers: Open the vouchers where currency was missing or wrong and reselect the correct foreign currency with accurate rate.
If needed, reverse incorrect entries and re-enter them properly.
You can also pass a Journal Voucher to manually write off or adjust the forex gain/loss balance, if it's confirmed as an error.
To prevent this in the future, always ensure:
Multi-currency is enabled.
Correct currency is selected in ledger and voucher.
Proper exchange rates are used.
To make this entire process accurate and easy, you can use XLTool – Excel to Tally Import Tool. It allows error-free voucher import with correct currencies and rates directly from Excel.