Depends on how many people want to do it. Say med science and not many engineering courses like science/engineering doesn't normally have any vacancies at sydney uni so maybe you would have to get over the atar cut off. But for say arts/science there's been vacancies for the past 2 years so they might take some just under the cut off, but i dont think 5 points under. That's a lot if you think about it when about 1000 people share 0.5 atar range (what i've heard but i know it's not linear) - less people share points at 90 than 70 obviously coz 70 - 75 is average. maybe go to the unis website you want and see if they have had vacancies in the course that you want to do in the past 2 years