Underwater, in the grass outside Sootopolis City.
Nothing evolves into Relicanth in Pokémon Emerald.
Relicanth dont evlove period.
no you do not have to catch a relicanth to get a rayquaza
no
relicanth doesnt evolve dumb bum
relicanth is a rare ancient Pokemon that can be found by diving near sootopolis city.
You can catch it when you use dive.
To catch relicanth use Hypnosis by Gengar and get lots of Dive Balls
no you can get a relicanth at the bottom of the sea
in route 226 and use super rod
on Routes 204/205/206
No only in ruby and sapphire and emerald.