after you beat the elite four he will most likely be found in water.
No, you can only get Latias in Sapphire and Emerald and Latios in Ruby and Emerald.
Latios can be traded to Colosseum from Ruby, or Emerald.
You can only get latias in sapphire get latios from ruby or emerald.
You can find Latios on Pokemon Emerald, Ruby, and SoulSilver.
Latios is not catchable in Sapphire you must get one from Ruby or Emerald.
No legendary Pokemon even latios and latias can have eggs.
One way is to trade with another emerald or you could trade your latias (or latios) to another emerald then restart the game and choose the opsite then catch it and trade back.
in the pokedex
The only way to get a latios or latias in your Diamond or Pearl is to migrate, latios from Ruby or Emerald. latias from Sapphire or Emerald.
to check where latios and latias are in pokemon emerald, you have to go to the pokedex, if you've seen them and go to the "area'' ICON.
Latios does not appear in water, but appears on grass and water(surf).
Latios is a legendary Pokémon in Pokémon Emerald version. When you encounter it in the wild it is level 40.