I'm in Kindle Select. Can I still list my book on NetGalley?

So far as I am aware, yes. However, this is a matter of debate. Amazon prohibits "sale and distribution of your book in digital format" while it is in KU. But arguably, NetGalley is an ARC distribution site, not a retail distribution site. I have had authors post their title on NetGalley while it's in KU, and they have not been penalized, but if you'd like to be on the safe side, you can contact your KDP rep and ask them.