How can I determine which instances types can be added to Parallel Cluster

This link addresses usable instance types.
https://docs.aws.amazon.com/parallelcluster/v2/ug/aws-services.html#amazon-ec2

Amazon Elastic Compute Cloud

Amazon Elastic Compute Cloud (Amazon EC2) provides the computing capacity for AWS ParallelCluster. The head and compute nodes are Amazon EC2 instances. Any instance type that support HVM can be selected. The head and compute nodes can be different instance types. Moreover, if multiple queues are used, some or all of compute nodes can also be launched as a Spot Instance. Instance store volumes found on the instances are mounted as striped LVM volumes.