IVEOS does not support IPv6 as of IVEOS 7.1. See also http://kb.pulsesecure.net/InfoCenter/index?page=content&id=KB18129
If you have an actual current use case, do get in touch with your Juniper AE/SE team to file an enhancement request.
Out of curiosity, what is the use case? Are you just future-proofing, or do you actually have client devices that don't have v4 connectivity?