How Margin Against Shares actually works?

Lets take an example:

Client at a certain broker holding following securities in his demat account:

XXX -100 Shares

YYY - 1000 Shares

If he wants to pledge 1000 Share of YYY which are trading @100 Rs per share in order to take a position in NIFTY future, the value of his pledged request will be

1000 * 100 = Rs 100,000.

If applicable haircut on pledged request is 25%, that means Rs 25,000 brokers keep for risk cover and release 75,000 for collateral margin. This amount will show as collateral value in your account.