The calculation of professional tax varies in India from state to state as it is governed by the respective State's Tax on Professions, Trades, Callings, and Employments Act.
As you are based in Chennai, the Tamil Nadu Professional Tax Slab will be applicable to you. As per the Tamil Nadu Professional Tax Slab for 2018-19, if your monthly salary is ₹10,000, you are not required to pay any professional tax because the salary is below the threshold of ₹15,001.
Here's a step-by-step guide to understanding how professional tax is calculated:
1. Identify the relevant professional tax slab for your state. In this case, it is the Tamil Nadu Professional Tax Slab.
2. Determine your gross monthly salary. In your case, it is ₹10,000.
3. Refer to the tax slab to find out the professional tax applicable to your income bracket.
4. If your monthly income is less than the minimum limit specified in the tax slab (₹15,001 for Tamil Nadu), you are exempted from paying professional tax.
Please note, these slabs might change every financial year so it's always a good practice to keep yourself updated. You can check the official Tamil Nadu Government's website or consult a tax advisor for the most accurate and current information.