I'm on IOT 49 as a Pilot and I got 123, I was told by those in the know that the recruitable mark currently is 121. Doesn't make you more competitive to get higher than that. They're looking for whether you have what it takes, if you do then they asses other areas of your personality to see whether you can work hard enough to exploit your score etc.
What I will say is that it's directly age correlated. If you are 18, then your chances of getting 121+ are drastically lower than if you are 21.
The majority of intake is in the form of 21/22 year old graduates as they are most likely to make it through flying training. If you aren't there yet, then don't worry if you miss out on 121. you'll have other opportunities to try again. Go to uni and join a UAS, if this is your dream then fight for it and don't stop until you get it. There are no golden tickets, everyone pays their way onto IOT in some form or another.