Actually I'm not from India. Yet I don't think CIC payment system is set up to distinguish by countries. I share your point, cause I had similar situation when wanted to purchase exhibition ticket online where it is stated that only credit cards accepted, I couldn't purchase with Debit card. However there was a case when I bought ticket with Debit Card, when the system was clearly stating Credit Cards only. As for CIC, it is not said whether it should be debit or credit card, but either VISA, MASTER or etc. card.