If you want to catch Latios or Latias in Emerald, follow these steps.
#1Beat the Elite Four. When the credits end, go to the TV. The TV will say something about a Pokemon soaring through the sky. Then it will ask what color it was. I recommend blue.
#2Wonder the Hoenn Reigon. Eventually, you'll find Latios or Latias
-SLICK
No, you can only get Latias in Sapphire and Emerald and Latios in Ruby and Emerald.
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.
randoom agen!
That's not possible latias and latios are caught in ruby, sapphire or emerald you must trade them to firered to get them.
you go fly in the air and catch him with a net
For Pokemon ruby you can catch the three regis, rayquaza, groudon, and latios/latias. In sapphire you can catch the three regis, rayquaza, kyogre, and latios/latias. However, in emerald you can catch kyogre, groudon, rayquaza, the three regis, and latios/latias.
It is possible, but you can't catch them both on 1 Pokemon game. If you have Pokemon Emerald, Ruby and or Sapphire. Then you can get them both. For example: Someone trade Latios and you have Latias, trade an another Pokemon for Latios and you have them both.
all i know is how to get the regis and latios or latias.
latios and latias appear in random patches of grass and areas of water after you catch Rayquaza or make him faint.(after saving the world in Sootopolis.)
The regis(except regigegas),raquanza,groundon,kyogre,and latios or latias
You can fight in the battle tower, catch the three regis, search for latios/latias, or in emerald you can catch groudon and kyogre
you cant catch latias or latios in diamond/pearl. you can migrate latias and latios from emerald, ruby, sapphire. in case you dont know, you get latias/latios at the end of the game and the mother tells you what color(red-latias/blue-latios) the guy on tv says. the hard part is to find it. it randomly appears any where on hoenn.