Can I configure DHCP Server on the Nexus 5010 ??
Seriously, I will not call the N5K as a core since it will not route traffic. IMO, I will use a switch which is capable to do 10G switching like a C6500 or N7K.
For DHCP request, on the C6K, in the interface vlan xx, add the ip helper-address x.x.x.x, where x.x.x.x is the DHCP server's IP address.