The 'opt out' option allows students to postpone their November 2020 exam attempt to May 2021. This means you won't have to pay any additional fees, as you've already paid for the November attempt. The ICAI is expected to launch this feature soon, with the link to be updated shortly.
in simple word it means, you can postpone your attempt to may 2021 and u won't have to pay fees for it as you have already paid it for nov 2020 attempt