What happens to the unspent exchange brought back to India?
The RBI has granted general permission to persons resident in India to hold foreign currency up to US$ 2000 or its equivalent for personal purposes. So, to that extent one can retain the foreign currency with oneself and the balance should be surrendered to the Authorized Dealer/full-fledged money-changer against the payment in Rupees. Such exchange needs to be surrendered within 90 days from the date of return if it is in the form of currency notes and within 180 days if it is in the form of traveler’s checks.
