As per the Income Tax regulations, in any financial year, if your international debit transactions (payments/spending) are more than INR 7 Lakh, then a fee of 20% (as of 1st October 2023) will be charged on the amount exceeding INR 7 Lakh (on the debits after the INR 7 Lakh limit is met).
For your DCB account, 20% will be cut on every transaction and will be refunded in 1-2 business days if it is charged before the threshold of 7 lakhs.