Ritchie and the RFU's plans will see a week knocked off to help create space for the new global season, which will be rolled out after the next Rugby World Cup in 2019.
"We think it would improve it," he is quoted as saying by BBC Sport. "It would narrow the 'off' periods and help with the broader narrative.
"It's absolutely right to always be thinking about what to do to enhance, improve and make the Six Nations better. We think it is a good route. It may well be that others agree or disagree."
The current seven-week format was introduced in 2003, having previously been staged across 10 weeks.