Call the Commercial Tax Department and ASK them. I live in Australia yet I can find the information quite easily for something I know nothing about!!!!
How can I pay my PT online in Karnataka?
Steps to Pay Tax on Professional Tax in karnataka
Step 1: Visit the Website of Commercial Tax Department of Karnataka for e-Payment of Tax.
Step 2: Click on Karnataka Professional Tax.
Step 3: Fill the information asked for.
Tax Details.
Step 4: Click on Next.
Step 5: follow instructions on the screen and Make payment of tax.