For future people. I struggled with IRCTC for hours trying to pay with a foreign card and failed. I tried 12go and it worked but they charged a R800 fee for a R500 ticket :P Cleartrip has worked in the past but they billed me and no ticket (I am confident of a refund).
But then I found the trick with paying in IRCTC via Atom. It is so damned counter-intuitive...but once cracked, it is easy.
Step through the booking process until you come to the
review booking page that looks like this
Click on Multiple Payment Service and you get this
And you are away. It took me 8 hours of frustration to get my first booking because the obvious place to click was
debit card with PIN. Once I worked this out it took about 30 minutes to do 4 more bookings.
The next challenge is the Indian railway system itself :P