You can migrate a domain that uses NIU Hybrid I/O resources. A constraint that specifies NIU Hybrid I/O resources is not a hard requirement of a domain. If such a domain is migrated to a machine that does not have available NIU resources, the constraint is preserved but not fulfilled.
Note that the NIU Hybrid I/O feature is deprecated in favor of SR-IOV. Oracle VM Server for SPARC 3.2 is the last software release to include this feature.