Instructions
Travel to Route 221 and make your way to the western area filled with grass.
Select the PokeRadar from your inventory list and use it. Tyrogue can only be found with the PokeRadar.
Step into a shaking pile of grass. If the Pokemon you encounter is not Tyrogue, flee the battle and use the PokeRadar again. Tyrogue has a 12 percent encounter rate, so it may take a while until you encounter one.
Use Psychic or Flying type Pokemon to weaken Tyrogue and use any Pokeball to capture it. Check its stats upon capture. If your Tyrogue's attack stat is not greater than its defense stat, you will have to capture another one. Once you have caught a suitable Tyrogue, raise it above level 20 to evolve it into Hitmonlee.