If you live in India then this is the APN setup for Aircel. Note that this is for 2G/3G/GPRS. You can also get these setting sent to you by sending an SMS with PI to 121. That would get the settings for you as well.
These settings are for the areas in India being: APN for Aircel -TamilNadu, Karnataka, New Delhi, NCR, Andhara Pradesh, Assam, Bihar and Jharkand, Chennai, Gujarat, Haryana, Himachal Pradesh, Jammu Kashmir, Kerala, Kolkatta, Madhya Pradesh, Maharashtra, Mumbai, North East, Orissa, Punjab. Rajasthan, UP East, UP West, West Bengal.
You can also see the setting here as to how to insert it into a Nokia phone. This would be the APN setup instructions for a Nokia mobile-phone.
Aircel APN for 2G/3G/GPRS
|Data Bearer||PACKET DATA|