Few Candidates have been able to access the uploaded images in the application form by clicking in the "Edit" option. If it is working for you too, you can upload the images. But the catch here is the correction window is only a one time option and if the uploaded images are not upto mark, then even if NTA notifies you asking you to upload the correct images, then you cant because you have already used up the correction window. So this is something that you need to think about and take a call. Ideally if NTA did not notify you to change the images, it means they are good.