Define doable. It is surely possible to make it from a gate in T2
to a gate in T3
in anywhere from 10-20 min depending on which gate, and how long you have to wait for the skytrain.
But, since I'm assuming you're an separate tickets, you'll have to stop by a transit desk, and pick up a new boarding pass. If you have checked luggage, it's a whole other story.
Plus, that's assumming your PR
flight is on time. A bit of traffic, a thunderstorm in MNL
, etc., and this is all gone. Better to take the later flight in this case, unless there's no big consequence for missing the earlier one.