Delayed Payment Charges or DPC can be a bit of a pain for users, but they only come into play in two situations.
Firstly, if your account balance goes into the negative, you'll be charged a DPC of 0.045% + GST per day on the negative amount.
Secondly, if you hold an overnight F&O position, you'll need to have at least 50% of the margin requirement in cash balance. If you don't, you'll be charged a DPC of 0.045% + GST per day on the shortfall.
To make it simpler, let's say the margin requirement is ₹1,00,000. You'll need to have at least ₹50,000 in cash, and the remaining ₹50,000 can be fulfilled using collateral pledge balance.