Alas, while researching this[1] article I discovered that there are no active WebRings still in operation. (the few sites that claim to be working webrings are in fact fake)
Webring.org is definitely still in operation. Take a look at a site like http://worldlighthouses.yolasite.com and try the Webring navigation at the bottom.
« Le webring de la salade » was still active only a couple years ago, and I personnally know some of its members, so I can probably get you into it if you wish. It's quite a niche webring though, and somewhat broken nowadays ;-)
[1] http://www.codersnotes.com/notes/under-construction/