Getting this message?:

Your Session has Expired.

This is how Babus in India manage government sites. This is not even a banking site.

So you get this message because IRCTC expires your session if :

1. You don't do any activity in your IRCTC while logged in, for around 5 minutes of time
2. If you press Back/Forward browser button
3. If you double click any button, link or even press F5.

What to do?

Use this trick to avoid session expiry.