How to check Internet Data Usage on BSNL 3G

Modem/Dialer: VISIONTEK
Network: UMTS/HSDPA
Plan: Prepaid

Open up the Dialer and click on the USSD icon on home screen. This will bring up the following screen:

Now, enter *112# and click Send. *123# also seems to work. An automated response menu should appear on screen. Send 2. You should be able to see a similar result:

[Sent]  *112#
[Received] Press 1 for main, 2 for GPRS DAY, 3 for SMS, 4 for Voice, 5 for GPRS NIGHT, 6 Credits by SMS, 7 to exit.

[Sent] 2
[Received] On DATA Pack u have 6Gb 186Mb 207kb valid until 27/04/2011  . Press 1 to return back to the menu, 2 to exit.

The result shows the balance data remaining on your recharge. If you do not have enough data remaining OR your subscription date has expired, this command will not work. BSNL would send an SMS to your number (SIM) stating that the command cannot be carried out. To check 3G Balance on your Mobile (if using BSNL 3G SIM on a mobile device), check this post.