This is an AIX related question, but still will try to answer it.
use mknfsmnt.
The mknfsmnt command is used for appending an entry to the /etc/filesystems file, thus making a file system available for mounting. If the mount is to be permanent, this entry remains. If the mount is temporary, the flags are used directly for the mount command.
Read this:
https://www.ibm.com/support/knowledgecenter/ssw_aix_71/com.ibm.aix.networkcomm/nfs_mounting_xplicit.htm