Creating /home partition on existing server without reformatting and adding new Disks

Hello,
We have a server with two disks (2 Disks) of 300 GB each, configured as RAID 1 (hardware raid). The vendor created default partitions and did not create /home partition while installing RHEL 7.2. When we asked them to create /home so that we can give quotas to users , they said they need another two disks and can not use gparted to create new partition as it is RAID 1.
Our question is there a way to create /home with adding disks or reformating disks. ? can Virtual file systems be used?