@Harkanwal deep singh You could recharge with International Call booster(Rs.24) on Airtel which brings down the call rate to 1 rupee per minYou should call the college's international students department or admissions office and ask them. They might have deferred your course or taken another decision and not informed you.
The call isn't that expensive either (it's ₹8/min from Airtel) but it's worth knowing what's the hold up.
A similar option should be available in other networks too