Dear Mihir,
The International selling guys at Ebay are a good team - try speaking to Amarjeet, he'll be able to help you. At the same time, you also need to have an import export licence, and some other documents.
India post is a good, cheap option, but there are other shippers too. You'll also need a clearing agent, as this will be an export.
Kindly note that you'll not incur any sales tax or VAT for international sales, as they'll be covered under "exports".
Good Luck in your venture on Ebay.in.
It's really fun being a part of this wonderful community.
WArm regards,
Illusions