We are using vcenter 6 and esxi 6 and using ip hash protocol. We have cisco switch with ethernet channel configuration. Now we have nas device and we want to add the nas device with isci protocol to vcenter. is it possible ?
Totally possible. You want to do your connection to the NAS at the ESX level. We have multiple remote sites, and we use NAS devices connected through iscsi for each one of them. Most NAS devices provide documentation on all the how-tos, so I'd suggest starting there.
Etherchannel and iSCSI is just asking for trouble, and you will be limiting your iSCSI design, here some good reading material. But as always, consult your storage vendor documentation.
Seriously, Stop Using Port Channels for vSphere Storage Traffic - Wahl Network
Avoid LACP with iSCSI Port Binding or Multi-NIC vMotion - Wahl Network