You cannot find Groudon in Pokémon Black 2.
How to find the captain on pokemon black2
Groudon and Kyogre are unavailable on Pokemon Ranger.
There is no Groudon in Pokémon Crystal.
Groudon is not in Pokémon Black.
Actually you will not be able to find a Groudon in pokemon black or white. It's because you will not be able to find a Groudon in the wild. The only way you can get Groudon in pokemon black and white you will have to trade with someone who has a Groudon or you can use Global trade.
Breed the volcarona that you find in relic castle (with a ditto if needed)
You get Groudon in Pokemon Heart Gold by trading with somebody who's found Groudon in Soul Silver. You can't find Groudon in Heart Gold, you find Kyogre. Soul Silver players find Groudon.
find groudon at the magma cavren and kyogre at marinea cave
Groudon is unavailible in Pokemon heartgold trade from soulsilver to get groudon.
Bianca
it cant
Yes, you can find Groudon in the map called "Fuchsia City". It is catchable.