Ankita, the uploaded images can be corrected only in NTA notifies you to do so. Let's say, NTA finds the uploaded photos, signature and thumb impression not falling in within the guidelines, NTA will notify you at your Registered Email Id and Mobile no#. Then when the correction window opens from January 15th to January 31st, you can make the necessary changes. But if you do not receive any notification, consider the uploaded images to be good enough.