Level 55.
You find larvitar in seavault cannyon. and then you evolve him into pupitar and tyranitar :) check serebii.net if you're wondering.
Catch a lavitar at island 5 and train it into a pupitar and eventually in the Pokemon league it should evolve into a tyranitar.
A Pupitar evolves into Tyranitar at lvl55.
pupitar and then tyranitar
Pupitar > level 55 > Tyranitar
Pupitar will evolve at level 55 into Tyranitar.
Evolve it from larvitar at level 30 to evolve it into pupitar then evolve it into tyranitar at level 55
Pupitar evolves into Tyranitar at Level 55.
Pupitar evolves into Tyranitar at level 50.
Pupitar evolves into Tyranitar at level 55.
You must evolve Pupitar to get a Tyranitar. Pupitar evolves at level 55. To get a Pupitar, you must first get a Larvitar. Larvitar evolves into Pupitar at level 30.
Tyranitar isn't anywhere in the wild in Pokemon FireRed. You will need to evolve it from Pupitar. It is required to get a Larvitar first, however; it is in Seavault Cave and can evolve into Pupitar at level 30, then Pupitar into Tyranitar at level 55.