I checked the packages running the cmd
# yum list *ssl*
but there were no libssl packages available instead there were libnussl and libnussl-devel available. I don't know if they are the same so didn't take a chance and looked for openssl packages. Installed openssl and openssl-devel and verified the configuration. Restarted the nagios and httpd service.
It's working now.
Thank you so much guys.
Can you also please explain why these packages were required and not listed in the pre-reqs.