The Swiss Chocolate train is a joint venture between GoldenPass services and Cailler-Nestle. Hence you get to journey on the panoramic train in first-class from Montreaux to Gruyères and Broc Factory and back. Thanks to large windows extending to the top of the train, travelers are able to enjoy the excellent views. Air-conditioning provides for comfortable, draft-free trips. From the Gruyères train station a bus takes you to the cheese factory. As part of the tour the patrons are served complimentary coffee and croissant on the train. Once in Gruyères you can also visit the ancient and medieval Gruyères castle. Then you board the train again for the trip to Broc, home of the Cailler-Nestlé chocolate factory, where you can watch a multilingual video and observe chocolate production. You are also permitted to gorge on the delicious chocolates and buy the Cailler or Nestlé candy bars at factory prices.

If you have a first-class Swiss Pass, Swiss Flexi Pass, Swiss Saver Pass, Swiss Saver Flexipass, Eurailpass, or Eurail Selectpass that includes Switzerland, you can travel on the Swiss Chocolate Train for only a reservation fee. When making reservations, specify whether you'd like to sit in a restored 1915 vintage Pullman car or a modern "panorama car" with oversize windows. This tour is seasonal and is operational only on Wednesdays and Mondays from June to October.

Pass Purchase - The Chocolate Train Passes can be purchased from Rail Europe in India. They have authorised agents who are selling the various passes mentioned above.
Rail Europe Agents in India

A list of some tour operators promoting the attraction:

Holiday Representation
Travel Corporation (India) Pvt. Ltd