Indian Railway Catering & Tourism Corporation [IRCTC] — about you site login security and issues on your site.

There is biggest weakness of your site is "phone number" can be repeated. According to your rules, One number can hold only one id but your add the new id on same number without verifying it... Only username will change but number will same... While input the same active id number, one error of " NUMBER REPEATED" will appear but the id has been save in your server and that person can login into it...
And your new site is unable to hold the traffic... It hang again and again.. fix is as soon as possible...