How do you get latios easily on Pokemon ruby?

Answer 1

There is no easy way to catch the roaming dragons without using cheats.

Even if you used mean look to keep it from running, it knows safeguard and refresh if I remember correctly, which will make catching it very difficult. You could try a Pokemon that knows mean look and baton pass, and another that knows false swipe. When you first encounter Latios, use the first pokemon's Mean Look, and then baton pass in the one that knows false swipe. Keep using false swipe as necessary so that HP is kept relatively low, and toss ultra balls and timer balls like no tomorrow.