Typically speaking, if you have never done any Japanese before university or knows of only the basic alphabet (hiragana and katakana) and basic grammar patterns, you can only major in the 'regular' Japanese studies major, where you start off in "Beginner Japanese". In the first 2 semesters, they basically cover both alphabets, about 50 or so Kanji (introduced at the end of 1st semester and some more in the 2nd semester), and the basic grammar patterns. From what I've known, it's about the equivalent of HSC beginners Japanese with some new grammar patterns, except it's taught much faster in 2 semesters as oppose to 2 years for the HSC. I know quite a number of people who have completed HSC Japanese beginner's course and wasn't able to take the 2A (or "Intermediate Japanese") course because they forgot a while lot during the summer break or didn't really understand the HSC course well enough. After the completion of "Beginner Japanese B", you should be able to pass the old JLPT 4.
But if you have done the HSC Beginner's course, and scored reasonably well, say band 5 or 6 or have done ok-ish in continouers, you should be able to start in the "Intermediate Japanese A", if your placement test goes well. At that level, about 10 or so new kanjis are introduced every week with many grammar patterns. If you've only done the HSC Beginners course, the chances are, you WILL find it difficult to keep up and there will be many things you may have not learnt in the HSC course... At this point, people either drop down to the "Beginner Japanese" (1A) course or they work harder to keep up with the workload. In the 2nd semester, sonkeigo (super polite language) and humble forms will be taught and if I'm not wrong, it's the biggest topic of that semester. Anyways, after the "Intermediate Japanese B", you should be able to pass the old JLPT 3.
Finally if you have done extensive Japanese studies whether it be on your own, with a private tutor or at school (many who start at this level have not only studied HSC Japanese, but also gone on exchange during or after high school to Japan), you may be allowed to start with "Advanced Japanese" (or 3A) depending on your placement results. And by starting at this level, you would be able to major in Advanced Japanese Studies instead of the regular one. I've heard that it's a huge leap from 2B to 3A (even bigger than the jump from 1B to 2A, which was already pretty major). In this "Advanced" course, you will have weekly kanji quizzes with at least over 20 kanji phrases and if my memories serve me correctly dictations of sentences every few weeks. At this stage, the textbook is also completely in Japanese.