By Completing the 1st 2nd 3rd 4th 5th 6th 7th and 8th gym then you will be able to unlock the 9th gym easy. I recommend you capture legendaries for this gym :)
its actually the 8th gym so you need 7 badges and then it will unlock
If you mean, "how do I unlock the Gym where he is", you have to go into the mansion and get to the basement. There you will find the key to open the Gym
You have to beat the 2nd gym.
awww by beating the 7th gym
win all 8 gym badges , meet prof.Oak and surf east from ur home.
Defeat every other gym. The Viridian City gym is actually your last gym, not your first.
go to it
The 7th gym leader in fire red is Blaine in Cinnabar Island.To unlock The gym, u must go 2 the pokemon mansion,search the gym key in the basement.
The gym in Viridian is actually the last gym. You'll unlock it after getting all the other badges. You should continue to Pewter through Viridian Forest.
go in the haunted mansion next to the gym and look in there it will be there
revive a pokemon from a fossil and beat the fire gym leader Actually, you need to get the key from the Pokemon Mansion. It wouldn't make sense to require you to beat the gym in order to unlock the gym!
you have to get the legendary in the game