F&O contracts of a stock enter the ban period when the open interest crosses 95% of the Market Wide Position Limits (MWPL). The ban is only reversed if the open interest falls below 80%. Learn more by visiting nseindia.com/products-services/equity-derivatives-position-limits.
You cannot take new positions for any stock F&O contracts during the ban period. However, you can exit your existing open positions. You can still trade the stock in the cash segment, where no such limits apply.
You can find the list of securities under the ban period on Zerodha's margin calculator.
Did you know? The ban period does not apply to index F&O contracts.