Les Bleus are set to open the tournament by travelling to Italy on February 6 before heading to Dublin a week later and Twickenham on March 13 but French authorities are worried about a new variant of Covid-19 in Britain and Ireland.
"We keep the first match. On the other hand, against Ireland and England we absolutely need to have the necessary guarantees from these countries," Maracineanu said at a press conference.
"There has to be proof that the other nations' virus framework respects the same requirements in terms of precaution.
"We expect the same thing from the other teams," she added.
Earlier, Maracineanu held a meeting with the French rugby federation to discuss the competition, which also features Wales and Scotland, and its virus protocol.
Other fixtures moved
On Monday, this season's club European Cups were postponed until "February at least" because of concerns about the new strain.
The French Top 14 and the Pro14 have moved domestic fixtures to fill the gaps over the next two weekends but the English Premiership is set to leave the dates empty for its clubs.
La Rochelle are set to host Bayonne on January 22 despite announcing earlier on Tuesday they have closed their training ground after 15 first team and academy players tested positive for coronavirus.
"The choice has been made to bring the last round planned during the Six Nations forward to maximise the possible use of that weekend to hold eventual new postponements," the LNR said.
Leaders Toulouse, ninth-placed Brive and bottom side Agen are the only clubs to have played their full complement of 14 matches while Bayonne have three games to catch up.
