Hi,
NFS v4 was very much supported from version 5.0 RU1 (Linux), refer to release notes below
http://www.symantec.com/business/support/index?page=content&pmv=print&impressions=&viewlocale=&id=DOC2723
For mount agent, specifying FSType would only be set to "nfs" as there is no option to put nfs4 as filesystem. However check below link on how to use NFSv4, I believe it is not the mount agent you need to take care rather you need to switch on an optional attribute in NFS agent.
Below link describes the sample setup of NFS
https://sort.symantec.com/public/documents/sfha/6.0/linux/productguides/html/vcs_bundled_agents/ch04s02s01.htm
For NFSv4 support, you might want to turn on the optional attribute of NFS resource, below link describes optional attribute
https://sort.symantec.com/public/documents/sfha/6.0/linux/productguides/html/vcs_bundled_agents/ch04s02s04.htm
NFSv4Support
Specifies whether to start the NFSv4 daemon rpc.idmapd or not and whether to monitor nfsd version 4.
Type and dimension: boolean-scalar
Default: 0
For using NFSv4
The NFS agent provides NFSv4 support to export shares using the attribute NFSv4Support. Only one of the Share resources that depends on the NFS resource needs a value of fsid=0 in its Options attribute. The shared directory that has the fsid=0 option becomes the root of all exports. The client needs to mount only this root file system instead of mounting all shares individually.
The syntax is:
mount -t nfs4 <server>:/ <mountpoint>
Always use a slash (/) to end the path after the colon (:).
All the file systems, other than the root file system, needs to have the nohide option set in Options attribute of share resources. Set the nohide option so that authentic clients can seamlessly move through the tree of exported file systems just by mounting the root file system.
To enable NFSv4 support on your node, you must have the rpc_pipefs (pipe file system) mounted on the node. At boot time, rpc_pipefs is mounted on every Linux node. In situations where it is not mounted, mount rpc_pipefs on the cluster node.
G