You can go to it by IP address (simple) or check the DNS configuration and correct it.
That is is not a good Domain naming scheme you have there. You might want to plan a migration from iocl.gov.in to iocl.gov.local to eliminate your DNS problems. Check the WWW dns entry in your local dns. Make sure it is pointing to the external ip address of your website.
You can use split-dns. This is where the internal DNS resolves to different IP addresses than the external DNS. However, in this case you want the internal DNS record to resolve to the external host IP address. Modify the internal record with the external IP address and things should work fine for accessing this host.