No. Siviper is in Sapphire/Emerald
Zangoose, the rival of Seviper, is in Emerald, Ruby, and Saphire. Zangoose is also in Mystery Dungeon Red Rescue Team and Blue Rescue Team.
In Sapphire and Emerald, you can find Seviper at Route 114. In Diamond, Pearl, and Platinum, Route 208(Sapphire has to be in the GBA slot.).
I need to use the bathroom
seviper does not evolve
You can only get Seviper in emerald
No. Siviper is in Sapphire/Emerald
You can catch Seviper in Ruby, Sapphire, Emerald, HeartGold (IV), SoulSilver (IV), Black and White.
Zangoose, the rival of Seviper, is in Emerald, Ruby, and Saphire. Zangoose is also in Mystery Dungeon Red Rescue Team and Blue Rescue Team.
In Sapphire and Emerald, you can find Seviper at Route 114. In Diamond, Pearl, and Platinum, Route 208(Sapphire has to be in the GBA slot.).
Seviper can be found in Route 114, which is south-west of Fallarbor Town. It is not accessible in Poke'mon Ruby, by the way.
I need to use the bathroom
You can't, you have to trade with Sapphire or Emerald. At least you get Zangoose! :D
To get Seviper, you have to have Pokemon Sapphire or Emerald (Zangoose is in Ruby) and you get it on Route 114 near Lanette's house.
You must trade one over from Pokemon Sapphire or Emerald. It is spelled Seviper, by the way.
You can't get it in Ruby. It's only available in Sapphire and Emerald, where you can find one on Route 114.
Sorry, but putting a Seviper first in your party cannot increase your chances of finding a Zangoose. Out of Ruby, Sapphire and Emerald, Zangoose is only catchable in Ruby, on Route 114. If you do not have Ruby, than in order to get Zangoose in Sapphire/Emerald, then you must trade it from another game.