I’m currently looking to book a train ticket from Varanasi to Agra in India. The cheapest option is to book directly through the Indian Railway Catering and Tourism Corporation (IRCTC) website. The Man in Seat 61 has an excellent guide on train travel in India. A must read if you are considering purchasing train tickets in India.
For the most part, the process of registering an IRCTC account works fine. I did have an issue with the SMS verification, but managed to complete it successfully after repeated attempts. The following are my observations based on my limited experience with the process:
Hopefully this may help you, but I may have just gotten lucky.