I had the same problem. However, then I realised that BB supports only 1800 Band while in India all service providers works on 800-1200 band, therefore you're not able to make calls from you BB device.
However, only Airtel supports 1800 Bandwidth.
Another Solution - If you go to any near unlocking shop, they will unlock your BB for just around Rs. 200 and then you can also use Idea, BSNL or Vodafone or any other provider on your BB.
Do let me know if you're still facing the same problem.