Can anyone suggest what station I have switch at while traveling from Rennes to Bordeaux, so that we can ride on the TGV? Do we have to go back to Paris to accomplish this?
If you look up the trip on www.sncf-connect.com you'll see the options .
Going to Paris is the fastest way and the good news is that you do not have to change stations. You just change trains at Montparnasse, meaning that a 15-min connection is enough. All details at the link above.
Thanks for responding