Is there a TGV train direct from Charles de Gaulle Airport to Rochefort, Nouvelle- Aquitaine? If so, how can I find a timetable for when it leaves?
There is not, there are no TGV trains to Rochefort. And no other services operate directly between Rochefort and Charles de Gaulle. You can see what train services stop at a French railway station on the SNCF web site.
If you are looking to make this route with the least changes, there are a few direct trains from Charles de Gaulle to Bordeaux (schedule times:) and where you can connect to Rochefort (schedule times:)
Depending on when you wish to travel, a number of strikes are expected until June. If you're planning on traveling before then be sure to check your exact date and double check nearer the time. Here are the current dates for strikes.