Hi Ankur,
On which port is the web server behind the load balancer listening? It is not uncommon to use a non-default port here. This is the port that must be specified in the HttpsPorts ACO parameter. This parameter tells the web agent that when it creates a redirect for any request that was received on this port, the protocol in the redirect should be https. If this web server is listening on default ports, including 80 in the HttpsPorts value should have worked and it would be best to open a case with Support for further troubleshooting.