If can get into UM, thats the best option .

Monash.au only if you intend to migrate .

They're both identical. Your testamur won't state which campus you graduate from. But, employers may ask, and some may view them differently.
What engineering?

For most engineering, if it isn't geographic-specific, then I don't see the need to pay more for almost equivalent degree. UTM/UM graduate often perform fine and on par or even better than Monash's graduate. You should opt for Monash only if you intend to go overseas, or want to exchange to Melbourne. Else, I don't think it's necessary to study in Monash.

For civil engineering, where geographic practice matters a lot, one thing to note is that Malaysia adopts Eurocode (EN) but Australia adopts Australian Standard (AS). While the base concept and understanding are the same, the approaches and design considerations are different so if you intend to work in Malaysia, graduating from an Australian university would mean you'll need to learn Eurocode on your own when you enter the workforce. Eurocode is pretty dissimilar from AS, but like I said the basic concepts are the same, so you can catch up. The question is are you willing to? One main difference is EN uses 1.35DL+1.5LL, AS uses 1.2DL+1.5LL but there's a capacity reduction. EN uses two formulae to calculate a steel beam bending capacity (one for sectional bending and another for LTB) while AS combines both into one formula by placing two parameters for each case (alpha s and alpha m). Common steel grade in Malaysia is S275, S355 but common grades in AS are 300, 350. They look minor, but once you scrutinise both codes, you'll find a lot more minor differences that would ultimately affect how you use them. Civil engineering is quite geographic-specific, and each country has different practices that unlike other engineering branches, though the concept is universal, the approach will not be.

This year saw almost half of the medical cohort secured internship/houseman in Australia ...a record