If you’re adamant about using tyranitar, X’s answer is great. However, I would recommend you get a female dragonair (iirc dragonair has to be female) to trade with the woman in Blackthorn city for her Rhydon (nicknamed Don). Since it’s a traded Pokémon Don will level up faster and it will handle Red’s Pikachu, Charizard and even Snorlax rather well. Heck, it’ll handle Espeon, too. Sure, T-Tar is immune to Espeon’s Psychic whereas Rhydon gets hurt quite a bit. Of course, you could just over level your team and make all of this moot.
But being able to level up more quickly and having an attack stat only four points short of tyranitar, I’d say Don is the way to go. :-)