I've installed RabbitVCS in a Debian testing platform (Trixie) using the distribution packages: rabbitvcs-cli, rabbitvcs-core, rabbitvcs-gedit and rabbitvcs-nautilus.
I intended to use it with Caja (I use Mate) but it did not work also following your instructions at

https://github.com/rabbitvcs/rabbitvcs/tree/master/clients/caja

No success also using Nautilus.

But giving the command "nautilus -q", I've obtained the following error

** Message: 12:53:13.151: Connecting to org.freedesktop.Tracker3.Miner.Files
Traceback (most recent call last):
  File "/usr/share/nautilus-python/extensions/RabbitVCS.py", line 30, in <module>
    from rabbitvcs.util.contextmenu4 import (
    ...<4 lines>...
    )
  File "/usr/lib/python3/dist-packages/rabbitvcs/util/__init__.py", line 25, in <module>
    from rabbitvcs.util.log import Log
  File "/usr/lib/python3/dist-packages/rabbitvcs/util/log.py", line 50, in <module>
    from rabbitvcs.util.strings import *
  File "/usr/lib/python3/dist-packages/rabbitvcs/util/strings.py", line 32, in <module>
    import six
ModuleNotFoundError: No module named 'six'

I've installed the package python3-six and RabbitVCS started working immediately for Nautilus.
For Caja it worked after I deleted the directory

~/.local/share/caja-python/extensions/__pycache__

and regenerated it with

caja -q

Hope this helps.