Where can you get giga drain on ruby?

Answer 1

Route 123 begins in the north on a long pier leading from Route 122. Fishing along the pier is blocked by stone barriers, however. At the end of the pier, the route curves to the west. East of this spot, a single Cut-able tree blocks access to a pair of paths through the forest. The north path leads to a trainer, Psychic Cameron. The south path leads to a Rare Candy in Ruby and Sapphire Versions, or to a Double Battle in Pokémon Emerald.

Back on the main path, Route 123 passes by a loamy soil patch containing three varieties of Berries. To the left of the soil patch is a girl who loves Grass-type Pokémon. If trainers speak to her while carrying a Grass-type in their party, she will present the trainer withTM19 (Giga Drain).