If you tried opening your irctc website, you might have seen the nginx error similar to the image below.
What is Nginx?
Nginx is a lightweight, high-performance Web server/reverse proxy and e-mail (IMAP/POP3) proxy, that is used mainly for load balancing on a cluster of servers.
Why are you getting this error-
The irctc software engineers have not configured their nginx to redirect properly.
How to solve?
There is not much you can do to solve this(since this would require nginx configuration changes), but you can try to do a hard reload of your website browser.
Press (control+shift+I) and do empty cache hard reload.