How do mega evolve garchomp in Pokemon indigo?

Answer 1

I get it ....

exp like u got a charizard , then u buy the mega stone call 'Charizardite X' or 'Y ' for it and when u battle with someone or some pokemon , just click item and click that mega stone ..... * one is enough.....from pokemonloverMY125

Answer 2

You would need a Garchompite from the Shop, then go into any battle and click on the tab called "Items". Your Garchompite should be in your Items if you have bought it, then click on the item if you have Garchomp in battle first or switched to it. It would mega evolve your Garchomp. This effect only last till the end of battle, but you keep the stone forever and has unlimited uses.