You can start as a sole-proprietor firm; but registering as a private company will put you in a safe place when huge unexpected losses are made; such losses can not claim your personal property. Better consult a chartered account.

The following registrations are usually necessary.

1. If it is a company, register with the Registrar of Companies. After registration, take 'Commencement of Business' certificate.
2.Trade licence from Muncipalty or Panchayat.
3.VAT registration with Commercial taxes department.
4.Registration with labour department if you open shops.
5. If it is a factory, register with Registrar of Factories and Boilers.

Better consult a chartered accountant.

Larry