okay i hope this helps, i havn't caught or even seen latias yet, but you need to go to saffron city and go into the building with an odd roof that is under the magnet train station, that is where the copycat lives, she will say that she lost her clefairy doll, to get that you need to go to vermillion city and go to the Pokemon fanclub, a fat guy will say he found a clefairy doll and he will give it to you after you tell him about the copycat girl, go out of the building and steven, from the hoenn region, will come towards you and show you a picture of latias and say that Latias came to the kanto region from the hoenn and he is looking for it, then you need to go back to saffron and give the copycat girl her clefairy doll then she will give you a magnet train pass, there isn't really anythin specail you need to do, because Latias is just roaming around the kanto region, I KNOW IT'S CONFUSING, but it's true, just comment if you need any other info. it's the same exact thing on soulsilver except with latios.
Yes, Mewtwo, Latios and Latias will be in HeartGold and SoulSilver.
goldenrod
Latias is a Dragon and Psychic type pokemon.
only latias is available
You need to defeat the champion again to make latias reappear.
In pokemon Heartgold
You can't get Latios in HeartGold. You can get Latias, to get her, talk to the copycat in Saffron and find her lost doll in Vermillion city at the fan club and Steven will be out there when you come out. He will talk about Latias for a minute and Latias will be in Kanto just walking around like Raikou.
You can't get to the Hoenn region in HeartGold or SoulSilver. However, Latias can be caught in HeartGold, which is a legendary from Hoenn.
you need your national poke decks to do this look on the map on your pokegear it wil show where latias is
latias or latios will show up on your pokegear map just like raikou and entei
it roams kanto after you get it on the marking map
If you mean Latias, it didn't feature in Pokemon Gold, but it did feature in HeartGold. You can find it roaming Kanto on HeartGold by using your PokeGear, there is only One Latias in the game.