Hey,
I'm not sure, because I had a hard time finding information on this. Can I use Redshift under the Houdini edu license? Does it have to be at least an Indie license? I'd rather ask before I buy a license. And can Redshift also be under the edu license at this point?

According to:

https://www.sidefx.com/products/compare/ [www.sidefx.com]

third party render engines work with the Educational license. (ie one provided through your school.)

Houdini Apprentice is not an Educational license. Third party renderers do not work with Apprentice.

If you want to be clear about your specific situation you should email sidefx directly.