5’6″ is a problem as it rules out quiet a few sports we’re not that good at (and you’d therefore stand a chance a quickly progressing).
Tall is needed for the rowing and is a hell of a help in the cycling (long legs = long levers etc.)
On the other hand one of the team GB men running the marathon has only ever competed in one elite level marathon – he won Berlin in 2hrs 10min and therefore qualified. He’s had a “gentle” go round the london marathon course (also being used for the games) to learn it but otherwise thats it! (by the way “gentle” in this context means he did a sub 3 hours!)
So some of the running events and the field events might be a possible…. how’s your shot-put?