All amendments are applicable from FY 2021-22 except for audit trail. None of the amendment applicable for FY 2020-21. However, professionals and various forums have advised to prepare relevant disclosures in FY 2020-21 so that comparatives are readily available next year.
Ammendments are applicable as and when the circulars are passed . The Companies are required to abide by the alterations. No only from assessment year 21 22 or 20 21. It's since time immemorial. Even all acts have the same rules.
If you happen to attend any webinars by the WIRC or any other regional council on Schedule III amendment, they would definitely verbally say on the webinar. There is no written confirmation.