Pokemon FireRed how to get Darkrai?

You can't get Darkrai in Pokemon FireRed. Darkrai is a Pokemon introduced in Generation IV (Diamond, Pearl, and Platinum) and is not available in older games like FireRed.

Here's why:

* Game Compatibility: FireRed is a Generation III game, and Darkrai is a Generation IV Pokemon. These games don't share the same Pokedex and are incompatible in terms of Pokemon availability.

* No Events: There were no official events or distributions of Darkrai for FireRed.

To catch Darkrai, you'll need to play a Generation IV or later game that features it. You can also potentially transfer it from those games to later generations if they support it.