Manual PTax Deduction in IT0015

Dear Experts,

   I have created one Custom wage type of MP00(9PTX) in IT0015 for Ptax Manual Deduction. I have modified the PCR INPX and inserted in the schema below INPX. But For testing when I maintain the value 1000/- in IT0015, it deducts only 800/-. This testing employee is belongs to Maharashtra which is having 200/- regular Ptax Deduction. But I want to dedcuct the Value 1000/- as it is maintained manually in IT0015.

Please find below the screen shots of same.

INPX:

ZN00.

RT:

Any help will be helpfull.

Thanks