You can reach Versailles by metro (RER) line C to Versailles-Rive Gauche station, located near the palace complex. The cost of the trip is approximately 3 EUR per person one way.

Also in Versailles, trains run from Gare Montparnase (to Versailles-Chantiers station) and Gare St-Lazare (to Versailles-Rive Droite station). Time on the road is about twenty minutes, the cost is also about 3 EUR per person one way. On arrival from the station, it takes 15 minutes to walk on foot.

You need to take the RER line C to Chateau de Versailles.