Hey Amanpreet, Not sure if I understood your requirement correctly but to change the load balancer URL of your HA deployed controller, you can use enterprise console to update it (which will eventually update the controller settings either visible on admin.jsp or .XML)
But I was just curious to understand how will you manage your existing agent endpoints? Are you going to change them at the agent config level? You cannot push agent config change from any console?
For such scenarios, I would recommend to manage the IP's at network and cname level rather than making a change at the controller.