The FreeDOS Alpha 6 distribution was released November 1997.
History
We don't have a complete history of the early FreeDOS releases. A mailing list discussion from 11/96 says we were discussing Alpha 6 in 11/96. So I wonder about the dates below:
Alpha 5 was released Aug 10 1996, and Alpha 6 was probably released 11/97 (that is, the 2006-doshist.txt file probably has a typo to talk about Alpha 5 when it should have talked about Alpha 6).
Announcement
We don't have an archive of the FreeDOS Alpha 6 announcement.