Discount percentage and Discount amount in sales invoice item table

Here is the scenario, my item amount is 100 which is tax rate inclusive with 15 % which means the item price is 86.96. so when i apply discount percentage as 10% it is taking the 10% of 100 rather than 86.96. How can i achieve this discount amount calculation based on net_rate rather than price_list_rate in the sales invoice item table. Any solution for this customisation?

Any one have idea on this customisation?

Have you tried Discount on “Net Total” option while applying discount?

hy pawan thanks for your reply. Actually i am taking about item discount percentage on inclusive tax rate not additional discount percentage. Any idea on that?
here is the screenshot