i saw a tip but it said the pokedex num was 243 but there is no num like that on my pokedex
this depends on your initial pokemon - which have you selected - Charmandor, Squirtle or Bulbasor?
also there is a specific trick on catching suicune, entei, etc (and they appear once throughout the game, if you fail, goodbye!!!)
please read a FAQ on it, it shows a way on finding and catching it. Its a secret in the game.
SQUIRTLE - RAIKOU (ELECTRIC TYPE)CHARMANDER - SUICUINE (WATER TYPE)BULBASAUR - ENTEI (FIRE TYPE)
TO FIND THEM JUST TRAVEL AROUND THE PLACE TRYING TO RUN INTO THEM....