Hi @Saqib 

As docs says

For each file server the number of FSVMs must be less than or equal to the number of nodes in the Nutanix cluster; however, you can create multiple file server deployments if needed. Each Nutanix Files cluster can support up to 16 FSVMs.  

Here’s the link Nutanix Files Architecture With your five node cluster the maximum FSVM that can be deployed is five and the minimum three. You can also create a “single node” FIle Server.