You'll need to trade for it or transfer it from the older Pokemon DS games. If you have a Gible you'll need to evolve it.
Garchomp and Gastrodon
Send it over from diamond obviously
What you do is, you got to any Pokemon center. Got to the second floor and trade with a friend that has it in diamond, pearl, or platinum.
You can't find garchomp or its previous evolutions in the game. You can see a garchomp if you battle cynthia.
Garchomp is a Ground/Dragon-type Pokemon, so it's weak to Dragon, Ice, and Fairy-type moves.
Can get one, in emerald its a fourth gen pokemon.
You can't. You need to evolve Gabite.
You can see Garchomp when you battle the Pokemon League Champion, Cynthia. You can find Gible on the B1F of Wayward Cave.
garchomp in hippowdon temple
she has a lvl 75 spiritomb, milotic, eelektross, braviary and lucario and a lvl 77 garchomp
Must evolve it or trade it.
in Pokemon ranger 2 i would say darkrai/heatran/garchomp/or charizard.