Theres nothing really set in stone afaik, some courses just involve an internal transfer which is just grades but others need to be done through UAC where 50% ATAR is considered. If you can transfer internally which i believe you can i'd say you want to be aiming for a distinction average, theres a chance that a little less than that might cut it but you dont want to risk it and first year subjects are the easiest. Definitely do not quote me on anything i've mentioned - just go talk to the student centre for law (i believe it may be the same one for business). I know someone who planned on transferring to law from business who talked to student centre and the impression i got from him was that it was not as difficult as you might imagine.
