Here's a link to the Reason 11 FAQ
https://www.propellerheads.com/en/re...ther-daw-hosts
Because Rewire is going away with R11 if you have any sessions that use Reason Rewired into PT you're going to have to keep your current version of Reason installed. Also you won't be able to host vst's in R11 when it's used as a plugin
Be aware that there are two versions of R11 and it looks like upgrading to R11 from whatever Reason version you have now does NOT get one the full Reason Suite. Upgrading to regular R11 is $129 and to R11 Suite is $249. Sounds just like the pricing games Plugin Alliance is playing with people