Different faculties have different requirements. However, you are generally expected to have at the very least a WAM of 70% and above. Score a CGPA 3.00 and above to strengthen your chances. I'm sure if you want to transfer in your second year those scores are very much achievable.

Note that not all units taught in monash sunway are recognised by UNSW/MelbU. You should take the initiative to find out which units can be credit transferred and which units you will have to repeat in the Australian uni. Besides that, to transfer to Clayton requires 70% and Caulfield requires 65%.