Anup, I have a Nokia XpressMusic model and am able to pair it with my Figo Audio system.
Instead of trying to pair your phone with the audio system, you should pair the audio system with your phone.
Try this:
1. On your audio system, keep pressing the menu button till you reach "Bluetooth ON". At this point keep the menu button pressed for a few seconds. This will take you to the Bluetooth menu.
2. Select New Device from the menu options.
3. System will display all the bluetooth devices in range. Your phone should be in that list.
4. Select your phone.
5. The system initiates a connection to your mobile and your mobile should prompt you to enter the password.
6. Once you enter this, your phone is paired and you can optionally say that this connection should be automatically estabilished. This will make sure that your phone gets automatically paired once you enter your car.
Hope this helps.