Which Octopre exacly ? Link pls. The one which I find with google has no ADAT ports.

Best is to use RME device as clock master, in the RME driver setting window set clock type to "internal".

If the Focusrite devices also have an ADAT IN, then it can recive clock as clock slave from the RME.

If such a ADAT IN port is not available or when you want to use your ADAT OUT ports on the RME for other purposes, then use Word Clock.

The devices need a digital input to receive a clock signal.
You say they don't have ADAT IN.
So you need to choose Wordclock, best with the RME as clock master for Word Clock.

Next time please be so kind to write directly, what interface you have.
I had to look it up now by reading other postings from you, so its an UFX...

Why don't you consult the manual ? In the UFX manual you will find a chapter about Word Clock, chapter 22.
There it is clearly stated:

[...]Output
The word clock output of the Fireface is constantly active, providing the current sample frequency as word clock signal.
[...]