Wouldn't matter what subject it was, a 65 just wont scale well. Anyway OP i checked your other posts and found your subjects, your subjects are all known to scale pretty badly if you don't go well and you already put them into an ATAR calculator yesterday and got a similiar result so i dont know why you think it's not right. I know you are probably heaps dissapointed but there are plenty of ways into uni, dw.It depends. If your 65 was from a low-scaling subject that your cohort performed at an average or less than average level, then it is possible. Also, they use your RAW marks, not your HSC marks for your ATAR, however to be on the sure side please contact them and ask why this is the case.
+1 but subjects do play a roleRemember the ATAR is a rank, it's not an average or anything of your aligned marks.