joyous tower has 99 floors
99
In Joyous Tower floors 11-15
Chikorita is a starter Pokemon or you can also getit from joyous tower floors 8-11 Chikorita is a starter Pokemon or if you haven't chosen it as one you can get it from joyous tower on floors 8-11.
You may recruit Eevee on floors 12-17 of the Joyous Tower dungeon.
nothing
joyous tower
In Pokémon Mystery Dungeon: Red Rescue Team and Blue Rescue Team, the Joyous Tower is simply a difficult bonus dungeon with no real goal at it's end. Joyous Tower does however contain many rare Pokemon specifically Chansey.
joyous
99
In Pokémon Mysery Dungeon: Blue Rescue Team, Chansey can be found as well as recruited in the dungeon of Joyous Tower, the floors that it can be found in within the dungeon would include Floor 50, Floor 60 and Floor 77.
if you are talking about Pokemon mystery dungeon red/blue, then there are 99 floors if your talking about something else then i don't know
at joyous tower 8-11 floors the recruit rate is 11.4% but if you enter joyous tower your level will revert to 1 but if you come out of there your level will become what lv you were before.