Hi,
"Manage-bde" could be used to verify remotely whether or not the computer is BitLocker enabled.
manage-bde -status -computername "COMPUTERNAME" c
**C stands for C drive*
https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/ff829849(v=ws.11)
Based on this, I found there was one script shared as below to query a number of computers with specified OU(only working for windows 10)
Query BitLocker status on remote computers
https://gallery.technet.microsoft.com/scriptcenter/Query-BitLocker-status-on-f44e443c#content
Hope this helps and please help to accept as Answer if the response is useful.
Thanks,
Jenny