Can I use the profits I made from trading in F&O to trade on the same day?

In case of derivatives, the settlement of funds happens on the next trading day i.e. T+1, hence your fund balance will not reflect the profits made by trading in F&O until they are settled by the exchange. Further, if the T+1 day is a settlement holiday, the intraday F&O profits will be available on the next trading day.