Aggron's primary weakness lies in its dual Steel/Rock typing, which makes it vulnerable to Fighting, Ground, Water, Grass, and Fairy-type moves. Additionally, its relatively low Special Defense means it can be easily overwhelmed by special attackers. While Aggron has high physical defense, it can struggle against Pokémon that exploit its weaknesses or use status effects.
I say AGGRON because it is a steel type and steel have the least weakness.
aggron
Aggron is a steel type Pokemon
You can't catch aggron but you can catch a lairon at victory road to get aggron train Lairon to level 42.
Aggron is number 306 in the pokedex.
You have to migrate a lairon or Aggron from ruby once you have lairon you must get it to level 42 then it evolves same with Aggron.
Aggron is a Rock and Steel type pokemon.
gyarados
Aggron can learn earthquake by using the TM on it.
that depends on your personal preference i personally think tyranitar over aggron
lairon evolves to aggron at lvl. 42 and aggron does not evolve
AGGRON! Rampardos's Attack is higher but his defenses are absolutely horrible.