If your talking about Pokemon Mystery Dungeon 2 Explorers of darkness/time then heres how:
1.Wait until you can go to a dungeon called Dark Crater
2.Meet with Creselia on the tip of Sharpedo Bluff
3. She will ask you if you want to go
4.You must go as a trio ( you, your partner and creselia)
5. Complete the dungeon which is 15 floors
6. You come to a relay point ( save your game )
7. Continue into the Deep Dark Crater Dungeon
8. When you finish Deep Dark Crater Dungeon which is 15 floors ( including the pit )
You will see Darkrai
9. You battle him and his minions
10. You beat them
11. You sort of beat the game
lets you see darkrai in Pokemon mystery dungeon 2
Darkrai is at Miracle Sea, but you need a Secret Slab or a Mystery Part.
Darkrai
Yeah Darkrai is in the Dark Crater dungeon on floor 13
in azurills nightmare. darkrai is the one causing the nightmare and is the boss of this dungeon.
you can evolve your starter pokemon
You have to beat the game to battle darkrai.
In Pokemon Mystery Dungeon: Explorers of Sky, Darkrai can be found in Dark Crater dungeon after completing the main story. You will need to defeat Darkrai and recruit him into your team to evolve your Pokemon by fulfilling certain conditions.
go though a dungeon with cresslia and when you reach the end you will fight darkrai
Then you have to beat Darkrai.
lets you see darkrai in Pokemon Mystery Dungeon 2
U find Darkrai in Dark Crater.