Can I use the profits I made from trading in F&O to trade on the same day?
The settlement cycle for F&O is T+1 days. This implies that when you make profits, it will be realised on the T+1th day.
Due to this, if you take an F&O position & make profits, we will not consider these profits while reporting margins to the exchanges, since the profits are realized on T+1. These profits will not be unencumbered balance on that day, and thus won't be considered as available margin for trading in F&O.
For Ex - You have 1lac margins in your account using which you trade in F&O and make profits of Rs 20,000. The total balance in your account will be Rs 1,20,000. Now if you take a position where margins required will 1,20,000, we would have to report that the available margins are Rs 1,00,000 and exchange penalty would be levied on the shortfall amount of Rs 20,000.
However, you will be able to use these profits to buy Equity (delivery) and also trade intraday, since there is no concept of margin reporting in the Equity cash segment.