Hello @Kalyan Reddy , Welcome to the Microsoft Q&A forum.
As per my understanding of the question you are using a Azure Load balancer and you have below requirement.
When i am using Load Balancer if the users are logged in and one of the server is down so the users should still login and continue their tasks as other server is up.
I think you can try the Hash Based Distribution model of Azure Load balancer . The hash is used to route traffic to healthy backend instances within the backend pool. The algorithm provides stickiness only within a transport session. When the client starts a new session from the same source IP, the source port changes and causes the traffic to go to a different backend instance. In order to configure hash based distribution, you must select session persistence to be None in the Azure portal. You can go through this documentation for configuring the distribution mode.
Hope this helps! Please let me know if you have any additional questions I will be glad to continue with our discussion. Thank you!