Bishal, a photo taken with a mobile has always a different and to be more specific lesser pixels than the photo taken with a professional camera. When NBE mentioned the dimensions, they have to be followed for the same resolution and pixel differences. Not to scare you but NBE opens its correction window only once and you have already utilised the same for uploading this photograph. Now you might not receive a mail asking you to rectify the photograph because the correction window has been closed. To be honest, if the photo uploaded doesn't fall within NBE guidelines, your application might be rejected and no admit card will be issued. You have to keep your fingers crossed.