This option is available to all users in case there is funds available for withdrawal. Instant Payout is available only once a day, for a maximum of 80% of the withdrawal funds (to adjust for any pending dues/positions).
Note : You can place only one withdrawal request (either IMPS or NEFT) in a 24 hour window, meaning if a request is placed at 3pm, the next request can only be placed on next working day at 3.01pm.