Savitha,  we understand that it is quite scary after preparing for an exam and committing a small error in the application form. We shall help you understand this issue with an elaborate answer so that you may feel at ease.

NTA accepts your applications online and they do not know Candidates personally. That is the reason they ask the Candidates to make changes in the application form on their own. For example, NTA doesn't know your date of birth and even if you enter it wrong, NTA will not know it. You are the better judge. The same goes with your academic details like registration number and roll number. It is within your jurisdiction to make the changes. Even if you do not now because this is not the information that will effect your merit, it is still ok. And as already discussed, it is not incorrect what you have entered because registration number is also correct. Now regarding the images, the servers capture the incorrect images and notify the respective Candidates. Now because you have already mailed NTA regarding this, you will have to wait to hear from them. And then let them decide the next course of action.