How do I know if the EMI payment process was successful?

As soon as you make your purchase on Tata CLiQ, you will see the full amount charged to your card. It will take the bank a few days (the time frame varies from bank to bank) to convert this into an EMI. 

From your next billing cycle, you will be charged the EMI amount and your credit limit will be reduced by the outstanding amount. For example, if you have made a three-month EMI purchase of ₹25,000 and your credit limit is ₹1,00,000, then your bank will block your credit limit by ₹25,000 and thus your available credit limit after the purchase will only be ₹75,000. As and when you pay your EMI every month, your credit limit will be released accordingly. For any further queries, you can get in touch with your bank.