You can only get Latias in Diamond by importing it from PalPark.
you cant. You can only catch it in Pokemon emerald, but, you cant catch latias in emerald.
need to migrate or trade
I think you mean latios or latias and you need to get them in Pokemon emerald, or you can use actionr eplay in Pokemon diamond. You can't catch it in the wild.
latias
In pokemon Heartgold
Yes you can. later in the game Latias (or latios depending on which game you have) is attainable. Like mesprit in Pokemon diamond and pearl and like mesprit, latias and latios tend to flee.
You can find latias on every route in hoenn.
Yes.
no way unless you trade someone. you can only catch it in Pokemon Sapphire, ruby, and emerald. i think if you have one, you could release it and catch it again. but who would try that?
Yes, Pokemon Sapphire version is the version in which you can catch Latias. You can only find it once you have beaten the Pokemon League, then there is a report of a legendary red flying Pokemon in Hoenn. Latias appears randomly.
go to eterna city and talk to a Pokemon called latias
You can't