Indy is now at 10.6.2 ...
Indy has been at 10.6.2 for a LONG time (since 2015!), but it has had MANY builds in that timeframe. Unfortunately, when
Indy switched from SVN to GIT in late 2019,
the build numbers broke.
That issue has not been resolved yet.
Is the documentation still being maintained?
Not really, no. It has not been updated since 10.1.5, I believe. Mainly because the system that originally created the documentation no longer exists, and a replacement was never setup. The current documentation largely still applies, there there have been a lot of changes made to Indy since that version, mostly internal, some public, but especially in the past decade for Unicode handling, additional platforms, etc, things that have not been documented at all.