What happens if I fail to pay the full amount within one trading day?

In case of using NRML as your product type while placing an order, if the amount is not paid before the settlement due date, i.e. one trading day (T+1) after the trade date, you will incur interest on the outstanding amount. At this point of time, we check if you have sufficient margin to cover the stock or not. If the margin is present, we mark the stock as beneficiary. However, if sufficient margin is not present, the stock is marked as pledged under Client Unpaid Securities Pledgee Account (CUSPA)

For example: If you buy a share on Monday (T-day), you need to pay in the amount by end of market hours on T+1 day. If the balance due is not received by then you will incur interest charges for the T+1 day, that is Tuesday. If you do not have sufficient margin present to cover your position, your stock is marked under CUSPA