Greetings Aisha!

If the picture uploaded by you is smaller in size, no need to worry but you can actually edit it once the correction window is open. Cat Application Form Correction facility will provide candidates to make changes in the uploaded images. The window will be provided in last week of September 2020. Keep a tab on the updates as to when the correction window is available. Also make sure the picture you upload is max 80kb size, scan and change the size beforehand. Also the picture in admit card and cat application should be same. Please go through this link. https://bschool.careers360.com/articles/cat-application-form-correction

Hope it helps!