You have to damage it's HP until it's very low, then you can try it with a timer ball, or a ultra ball, nest ball, dusk ball, luxury ball, (great ball).
Any.
With your hands and cover your face or the ball can hit you and give you a bloody nose
I can't remember where to get the quick ball but that's what i caught mine in and it worked pretty well.
probably ultra or time or speed depending on how quick you try to catch it
master ball
A quick ball would be helpful for the first few turns if we're talking platinum.
use a master ball
A master ball
The best ball to catch Deoxys is a Master Ball or a Timer Ball! Trust Me!!! Pokemon Master
the ultra ball is what i used to catch it...but you could use the master ball after you get it
master ball
Master ball