Mrunal, NTA notifies Candidates generally a few days before the correction window starts. Such Candidates who have been notified only can make changes to the uploaded images during the correction window. Again NTA should consider the images not falling in line with the guidelines and only then will you receive a notification.

dear Mrunal sahare,

Generally NTA sends a message to every candidates  regarding correction in neet ug application form but you don't need to wait of any message if you want to do any correction in your application form because during 15 jan 2020 to 31 jan 2020 the neet ug correction window open for every candidate who applied in neet ug 2020.