Splunk will support you on Splunk issues if you're running on Veritas Cluster Server, but can't support you on Veritas issues as that's really your responsibility. That said, here is one way in which you can set up Splunk under Veritas.
Put each Splunk instance into a Veritas service consisting of and depending on:
Dedicated storage for that instance
A virtual external IP and DNS name for that instance
The corresponding Splunk executable and configuration files for that instance, stored on the instance storage
The running application and associated monitoring/control of the application state
Each instance is normally expected to run on a single physical cluster node. But to allow any instance to run on any node, you should also set configuration to ensure no conflicts by using different values for the following for each instance:
File paths of the Splunk installation home
File paths of the Splunk data indexes
Network port numbers for Splunkd API, SplunkWeb, Splunk TCP input, Splunk TCP-SSL input, and any other network inputs
Forwarders should forward to the Virtual cluster address of each instance, using the corresponding input port numbers for each instance.
Search heads should query against the Virtual cluster addresses of each instance using the corresponding Splunkd port number numbers for each instance.