My friend is going to get Airtel Prepaid simcard from Mumbai or Bangalore. Which circle will be cheapest option for Mobile Office.........? and may I go for Lifetime prepaid or some other voucher........... as there will be little incoming/outgoing. Can it be recharged in other circle.........? I heard 7/- per day scheme in Mumbai............ can it be activated and deactivated easily and any charges for the SMS for activation/deactivation? I want uninterrupted MO for atleast 1 year