In Aviation, there may be a specific subject or educational pass requirement, but as others have said they’ll look at how you perform in the airline selection process as the sole measure of grading you individually.
The truth is, not just in Aviation but for every field, your ATAR score is one of the most irrelevant things in your life. The emphasis placed on it as a measure of success is totally unjustified despite your school, your parents and the media telling you it’s one of the most important things in your life. It isn’t. It’ll only really affect you if you want to go into a University course with a minimum ATAR score next year. Apart from that professional employers don’t care how well you achieved on a memorisation and regurgitation exercise when you were a hormone affected teen, they perform their own aptitude selection testing. You’ll realise over time how inconsequential the mark is. Personally, apart from a uni application straight out of high school I’ve never been asked about that score ever again.