- On the last day of the contract— the last Thursday of the month—next month’s contracts would be eligible to trade.
Read the in-between lines of above statement.
Contracts will expire around expiry day 3:30 cash market closing session. Only next month contract for the evening session.
That's easy.. But, the in-between line is Stock Futures will be available so that 3:30 pm settlement(physical settlement).
If it is only index derivative no one care settlement time 3:30 or 11:55.
So, smart guess: Stock F&O is also available sooner or later for the extended session.