We have a feature on the order window that displays the margin required for a trade before placing the order. The margin required is updated in real-time based on the product and order type selected. 

For Futures and Options Positions, the margin required for placing the order is determined after considering the margin benefit if you have any hedged open positions available.

Also, while squaring off or exiting positions, the order window shall display the margin required. This means that margin used will go up by that amount after closing the given leg.

Note: Sometimes, you might find small differences in the margins displayed on the margin window and what is blocked on the terminal.