For all stocks traded in the F&O segment, the exchanges set an MWPL(Market-wide positions limits), this is the maximum number of contracts that can be open at any time(Open Interest), If the open interest of any stock crosses 95% of the MWPL (All futures and options contracts of that stock), all F&O contracts of that stock enter a ban period. When the stock F&O contracts are in the ban period, no fresh positions are allowed for any of the futures and options contracts that are in that stock. You will only be allowed to exit the existing positions during this period. The ban is reversed only if the open interest falls below 80%.