You can override the system-calculated Income Tax by manually entering the tax amount.
Go to, Run Payroll >> Run Payroll >> click on Override Income Tax
Search and select the employee
Enter the Income Tax amount which needs to be overridden and
Click on "Save".
You can also Override the Income Tax amount in bulk by clicking on 'Import list to override Income Tax'
Download the tax update template
Update the amount and import
Note: Override Income Tax will work only if Income Tax Computation is chosen as 'Compute for this month’ OR ‘Use previous month's TDS’ options.