IdanMamo you could only install Beta 1 for 2a on the build number before recent 2.6 updates. Then, if you didn’t install Beta 1, there is no way to join Beta 2. Sorry.
Stable release is planned for this month, so hold tight for that update.
Omid - December. However, you are in the right place to find out! When there is news of a date, it shall be shared on this Community site, first.