Just tried out 1 of their groups - lasts 90 minutes. I guess it was a lot like what used to happen here on MS on Sunday Nights (Healing Circle, I think).
they limit it to 10 male participants and a few mods. Strict rules but there for a reason. It was nice. Not a lot of structure beyond the rules - just a lot of sharing. They have meetings 5 days a week.
It's a different set of rules to participate with 1in6.org. The biggest difference being that 1in6.org is moderated by a professional therapist fully-licensed in the field. Not that this makes it more credible, but it does make a big difference in how participation and contributions are monitored and how differently participants and volunteers are welcomed and addressed.
Another alternative is RAINN.org.
Regardless of the format and approach, they're all on the same team.