is corona renderer 6 rc1 or daily build 7/21/2020 newer?

Corona Corona for 3ds Max Previews
1

RC1. When in doubt, you can always check the daily changelog thread :smiley:

2

Yep, here: https://forum.corona-renderer.com/ Corona Renderer 6 for 3ds Max - Daily Builds Changelog
Also, once you install Corona, the build date is printed in Render Setup > System > About Corona.
You can easily switch between different versions using this method: https://coronarenderer.freshdesk.com/support/solutions/articles/12000066819