How to take a vat number

Both natural persons as well as legal entities can get themselves registered under VAT. Are you eligible to get registered? Check out the criteria found in the Commercial taxes website 

VAT replaced sales tax in most states, so the answer would no. A VAT Registration number should be sufficient.

If you qualify as a "dealer" - someone in the business of buying and selling goods - and you meet the threshold requirements of turnover - usually around 10L/yr (but varies from State to State) - you are liable to register as a dealer with your local commercial tax authority.