Originally Posted by
DCJoe1
I know the RER isn't perfect, but I wouldn't chance the traffic. RER B to Denfert-Rocherou, then the 6 to Gare Montparnasse. Should be about 1:05 or so from exiting customs to getting off the 6 at Montparnasse. And only 10 euros.
Depends upon how much luggage he's got, and I don't recall the RER/Metro 6 connection at Denfert-Rocherou. OK, did some research, doesn't look bad. RER is at a higher level; the TripAdvisor thread says there are also elevators available.
This sounds like a practical plan to me.^