To add an ESXi host in a cluster in vCenter, follow these steps:
1. Open vSphere client and log in to your vCenter Server.
1. Navigate to the Cluster view by selecting the cluster you want to add the ESXi host to.
1. Click on the “Actions” dropdown menu and select “Add Host…”
1. Enter the IP address or DNS name of the ESXi host you want to add to the cluster.
1. Enter the login credentials of the ESXi host and click “Next”.
1. Review the summary and configuration options for the host and click “Next”.
1. Verify the network settings for the host and click “Next”.
1. Configure the storage settings for the host and click “Next”.
1. Review the final summary for the host and click “Finish” to complete the process.
The ESXi host should now be added to the cluster, and its resources will be available to the virtual machines running in the cluster.
