I'd suggest that Jordan's six rings are a more impressive accomplishment because in Russell's heyday there were only eight teams, and two rounds of playoffs required to win a title.
An argument can be made that with only 8 teams, the talent level of each team was greater. With more than 30 teams, the talent level is diluted.
Also, the game wasn't nearly as athletic as it is today. Russell was a great defender and rebounder, but he couldn't score a lick. Jordan did everything. And look Russell's supporting casts; First Cousey & Sharman at the guards, then the Jones boys. Not to mention Heinsohn, Havlicek, and a host of others. Jordan had Pippen, and that's about it.
Russell averaged over 15 points per game for his career. I wouldn't exactly say that he "couldn't score a lick". And he averaged 22 rebounds a game along with what many people estimated to be anywhere from 8-10 blocks per game. A lot of people make a big deal about Oscar Robertson's 61-62 season where he averaged a triple double. It's quite possible that Russell averaged a triple double for his entire career, had blocks been an official statistic in those days. And the reason that Russell had such a talented supporting cast was due in large part to the higher level of talent that I mentioned earlier. Every team, not just the Celtics, had loaded rosters. Wilt played with Hall of Famers Billy Cunningham and Hal Greer, as well as all-stars Chet Walker and Luke Jackson when he was on the Sixers, yet they still could not get past Russell.
Russell was definitely the dominant player of his time and for a longer period than Jordan, but Jordan dominated under much, much tougher conditions, IMO.
Jordan also did not play in an era where there were several top-flight players at his position. Russell had to go against great centers such as Chamberlain, Dolph Schayes, Walt Bellamy, Nate Thurmond, Willis Reed, Elvin Hayes and Wes Unseld. Jordan never really had a hall of fame-caliber 2-guard that he had to face, other than maybe Clyde Drexler.
Admittedly, I was not born until 8 years after Russell retired, but I have read a lot and looked at the statistics and I would have to say that you can't argue with 11/13 championships.