im not sure how the current situation is, but last time back in 2000, if you applied for both and got excellent results in PMR, sure got offered by SBP first. Say bye2 to mrsm lah. Unless SBP didnt choose you, then u stand the chance to go to mrsm.

both sbp and mrsm also have pros and cons. just go if you are accepted and experience it! Teaching is excellent though in SBP.