Hi 
I need $lookup among sharded-collections, that is supported since from 5.1.
We have MongoDB on premises. Do versions 5.1/5.2/5.3 are about to be released for production on-premises (community edition)? Or the next formal community edition will be 6.0?
And is there planned release date for the next community edition (5.1+/6.0)? I couldn’t find any.
Thanks!
Welcome to the MongoDB Community Forums @Yaakov_Shoham !
Quarterly Rapid Releases (5.1, 5.2, 5.3) are available as development releases via the MongoDB Download Center or as an opt-in for dedicated MongoDB Atlas clusters (M10+). Rapid Releases are fully supported on MongoDB Atlas, but not recommended for production use on-premises as they haven’t gone through the same extensive cross-platform qualification as a full GA release.
The next major annual release series will be MongoDB 6.0 later this year. For more information on the release schedule and some common questions, please see: https://www.mongodb.com/blog/post/new-quarterly-releases-starting-with-mongodb-5-0.
A specific release date for MongoDB 6.0 GA has not been announced yet, but per the quarterly release schedule you should expect the 5.3 rapid release this quarter and 6.0 GA the following quarter.
If you are interested in following new release updates, they are posted to the Server Releases category. Click on the 
in the top right of a category or topic list to see notification options, or see Managing and subscribing to notifications for further preferences.
Regards,
Stennie