Hi Prasad
At my first impression, I would probably tell you about the Swiss Travel System for 3 days. All the information you need about it can be found here. Please, read it carefully 🙂
However, so that we can be sure and advise you better also on tourist trains such as the Glacier Express, please call us on 0041 848 44 66 88 (0.08/min) or, if this number does not work, on 0041 51 225 78 00.
I wish you a great time. EllenvS.