Have you enabled your T1/T0 routers to pass multicast traffic?
https://docs.vmware.com/en/VMware-NSX/4.1/administration/GUID-6AAC3360-4F79-4FBF-BCC1-0D8C220B0621.h...
Like most multicast routing it has it's own setup, depending on your setup you may need to configure it on your Nexus as well to route.
