well, i'll say just go try! but then if he is really shorter, like no matter what he is shorter than 1.65m then.. he will still be rejected. they are very strict about height.
so it depends on himself, whether he can face the disappointment or not.. it's a very personal choice.
if you know that he is not going to meet the height requirement, then there's no point in convincing him to go, you know. if you have to convince him, that means he doesn't really want it or he is not confident enough, or that he knows he is not tall enough.
but if he's like, 1.65m and afraid that he will not pass it, then you should convince him to go.
hope it helps.

when strange things happen, they call it fate.