It sounds like you might be mixing up your Layer 2 (VLAN) and Layer 3 (SVIs and routed interfaces) a bit. Your 6509 interface is a non-routed port. Is the Mgmt VRF you mentioned available over VLAN 1900? e.g., you would need something like:
interface vlan 1900
ip vrf forwarding mgmt
...in your config.
Otherwise the default routing table (RIB) on the 6509 will be servicing layer 3 requests on Vlan 1900.