Have purchased 2 CRS326 for q-in-q implementation. As per manual I can't find ingress-vlan-translation command under interface-ethernet-switch.

Do I need to change OS to get this feature?

Currently this feature is not supported with hardware offloading, we are working to implement this option, but there is no ETA yet.

I just want to add on this.

Our supplier doesn't stock the crs1xx versions so we are literally having to go to site and recover old switches to get q-in-q