It Depends.
If your Tyranitar have the Sandstream ability, invest more EVs in Defense and HP rather than Special Defense, because sandstorm boosts the Special Defense of Rock types (Like Tyranitar) by 50%.
So, I would say that 252 HP/180 Defense/76 Special Defense and a Careful nature, or 252 HP/252 Defense/4 Special Defense and again, a Careful nature.