The sixth gym is flying type so get an electric type and train it to a high level then go against the gym leader and keep battling her until you beat her. If you can't get to the gym go past that town and keep going along the route to Lilycove and you will see Steven. Talk to him and he will give you a Devon scope. Use the Devon scope at the place where it won't let you pass then a Pokemon will run away into the trees. Then the path to the gym is clear.
The sixth gym in emerald...is the gym in fortree city....and the leader is winnona...
The Fortree gym.
BEAT THE GYM
Fortree City.
The sixth gem is with Leader Winona in Fortree city. You need surf to get to that city. You get surf from Wally's dad after you beat the fifth gym. You surf there from Mauville.
I am not sure but you can go to gamefaqs.com and they have free strat. guides written by people who have beaten the game
Defeat all of the Gym leaders on Emerald. ~KKMG1
Fortree City.in fortree city
The sixth gym in Pokémon Ruby, Sapphire and Emerald is located in Fortree City. The gym leader is Winona, who uses flying types.
Go in. Beat the GYM. THAT SIMPLE
after you beat your father's gym
beat the 8th gym