This feature is available with a NetScaler enterprise or platinum edition license.
A NetScaler cluster is a group of nCore appliances working together as a single system image. Each appliance of the cluster is called a node. The cluster can have one appliance or as many as 32 NetScaler nCore hardware or virtual appliances as nodes.
The client traffic is distributed between the nodes to provide high availability, high throughput, and scalability.
To create a cluster, you must add the appliances as cluster nodes, set up communication between the nodes, set up links to the client and server networks, configure the appliances, and configure the distribution of client and server traffic.