Gazette Notification Update
The Gazette Notification is expected to be released by November 2016. I suggest you wait for the notification. I even inquired with ESI officials, and they are not clear on this.
There are two possibilities:
1. The effective date can be from the date of the Notification, from 1st November 2016, or any other date after the notification date.
2. Since the contribution period is starting from October 2016, they may consider it effective from October 2016. However, it practically has many issues, so I don't think this is possible.
Therefore, I suggest you wait for the official Gazette Notification. However, inform your employees that this is happening.