......
Spoon feed you one time... Since you're only 15... You barely know any of these things....
MBBS, MD, MBChB, MBBCh, MBBChir, MBChB BAO, BM, BMed, BMBS, BM BCh...
Semua sama barang...
Usually based on your title, people can agak agak and know where you graduated from.

If you're given a MBBS which the majority of the medical schools in the world uses, people will know that you're a doctor... But can hardly guess where you graduated from....
If you're given an MD, people will think that you graduated from the US... But, you can also graduate from UKM and end up with a MD degree...
If you're given a MBChB, people can think that you graduated from Egypt.. But, you actually graduated from Glasgow...
If you're given a MBBChir, people will definitely know you're a smart ass who graduated from Cambridge because only Cambridge awards MBBChir to their medical graduates....
If you're given a MBChB BAO, people will know you graduated from Ireland... so forth and so forth...
Simple as that... They are the same thing...

It's good to plan ahead...... But there's lot more things to consider other than fixing yourself into the doctor's pathway. =)
You're still young... You've got many options...

TJU is a unique partner medical school with IMU. The partnership between TJU and IMU is established because there's sort of like an agreement between the US and Malaysian government to actually help train doctors for Malaysia in the american style of medical education... This is why, TJU only accept Malaysian students (not for international students)...

Let's say 5 years down the road, you've come into IMU, and you've made it into semester 5 which a thing called the "matching process" that would take place during that time, you'll be asked to rank your choice of universities in a list with all the partner medical schools on it. So you rank them 1-23... which one you want, you rank them 1st...

But, if you want TJU, you'll have to "opt out" from the matching process.... You will compete against with your other peers, who's dying to go to TJU also, just like you.... TJU only accepts 6 students per year.... And usually around 10 students will fight for the mere 6 places, and I can say that the competition is very strong.... You all will compete based on your USMLE part 1 results, the one with higher marks will get the place.

As for the remaining students who did not get TJU, they will either be offered in any of the PMS or in a case where there's no leftover places in the PMS stream, you'll go to Seremban.

I hope the information that I've given is clear and accurate.
If there's anything I've mentioned wrongly, sorry har...

USMLE Source: Wikipedia

The United States Medical Licensing Examination (USMLE) is a multi-part professional exam sponsored by the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). Medical doctors with an M.D. degree are required to pass this examination before being permitted to practice medicine in the United States of America.