in viradian city
Gym Leader Blue
blue in viridian city
you can take on any gym leader in kanto in any order (excluding blue you have to battle him last)
Red is in mt.silver and blue is the eight kanto gym leader
to battle Blue in Pokemon Heartgold you must defeat the 7th gym leader, then find him on cinnabar island. Talk to him, then he will go back to his gym for you to fight
He is the Gym leader in viridian city
After beating blue, the 16th gym leader
Machamp, Arcanine, Exeggutor, Rhyperior, Tyranintar, Pidgeot. I made a link of all gym leaders, blue the gym leader is at the bottom.
Clair and she is the leader of blackthorn city or if you mean the kanto leader its blue/Gary ashes rivle
Red is at the top of Mt. Silver. Blue is the Viridian City Gym Leader.
In Pokémon HeartGold, you can find the 3rd Gym Leader in Goldenrod City.
no you can not become a gym leader in any game.