Paris to Versailles - RER C not running

www.ratp.fr/en can give you suggested routes and the details of the route (like if it is flooded) that I suggest which is to take the local Dreux bound train (Transllien Line N) from Gare Montparnasse and exit at Versailles Chantier which is a 5 minute bus ride from the palace. Good luck, flooding might not be your only issue. I think that there might be some strikes planned that could affect the Transilien lines.

Edit: I just thought of another Route. Metro Line 1 from Bastille to La Defense. Transilien train (I forget the letter but you can get the exact routing at ratp.fr/en) from La Defense to Versailles Chantier and walk or bus to the palace.

Unfortunately the Line N is also one affected by the floods.

This link provides a link to see what trains are running on Line N:

http://www.transilien.mobi/trafic/detail?listIDs=27080

This link shows how to take a train from Gare St Lazare to Versailles Rive Droite station, then a 20-minute walk to the Chateau. This is a Transilien Ligne L train and takes about 40 minutes -- but during the strike only 2 out of 3 trains are running. Luckily you'll be going against traffic so you should be able to find a seat (maybe I'm guessing wrong, but I think that!).

http://bienvenue.chateauversailles.fr/fr/vue-generale/gares#!panel-0-subpanel-2

You can go here to find out when trains are available. Type in from Paris Saint Lazare to Versailles Rive Droite.

http://www.transilien.com/horaires

(at the above link you can also check what availability there is for the Ligne N train that JHK mentioned above, and see which one will operate better for your schedule).

Good luck.

There's also apparently a special bus that goes directly from the Eiffel Tower. There's one at 8 am and then one at 2 pm

http://en.chateauversailles.fr/prepare-my-visit-/single/access

Thanks so much! We will check it out.

Line L also stops at La Defense (that first post suggesting to go to La Defense and take a train to Chantier was incorrect - that train (the Line L) goes to Versailles Rive Droit). It's an easy walk from Gare Rive Droit to the palace through central Versailles.