I see from the site for the Paris Metro that there are closures on the RER A during this time but I am unsure if the RERC also has closures because I can't seem to find that. And when you try to check itinerary, from the station closest to our hotel, which should be the St Michel-Notre Dame station to Versailles the route is not on the RER C until I think the Javon station? Just trying to figure out the best way to get from our hotel, Citadines St. Germain to Versailles?
The Citadines St Germain website states that you can get there using RER B, as well as Metro lines 4 or 6.
You probably meant Metro Javel, but you could go to Invalides to take RER C, though that would take more time than it would be worth.
Sometimes the RER C has stations which are undergoing work, so you can't access them.