Following the launch of “Jadoo” by MTNL, state owned Bharat Sanchar Nigam Ltd. (BSNL) has launched 3G cellular services in India.
The service offers 3G voice and data plans. Head over to http://bsnl.co.in/newsdetailed.php?news_id=448 for tariffs and chages.
BSNL has put up a pretty good FAQ sheet to clarify your queries here: http://www.bsnl.in/faq/faqans.php?paramCategory=3G%20Mobile%20Services
In case you wish to register online for 3G service, you can do so here: http://portal.bsnl.in/bsnlccp/New3GuserReg.aspx
