Hi Temo 

you can try.

Hermance Région Rugby Club (HRRC)

Dan

http://www.lifeingeneva.com/#!sports-clubs/c17rr has list of sports clubs. 

Also Cern has perodic open enrollments, usually advertised here or you can check: 

http://cern-rugby.weebly.com/

Thanks a lot guys - will check them out!

There is also Geneve-Servette rugby club, founded this year playing in French league 4:

http://www.servettercgeneve.ch/en/About-us/About-us.html