Can I use Quaquaval's "Up-Tempo" Ability to put a card from my hand on the bottom of my deck if I have 6 or more cards in my hand?
No, you cannot. You have to be able to draw a card when using this ability.
Up-Tempo




×2Up-Tempo
You must put a card from your hand on the bottom of your deck in order to use this Ability. Once during your turn, you may draw cards until you have 5 cards in your hand.

Hydro SplashDancing in ways that evoke far-away places, this Pokémon mesmerizes all that see it. Flourishes of its decorative water feathers slice into its foes.
Can I use Quaquaval's "Up-Tempo" Ability to put a card from my hand on the bottom of my deck if I have 6 or more cards in my hand?
No, you cannot. You have to be able to draw a card when using this ability.