Need confirmation on how iSCSI RAID storage works

is the RAID level of the storage where the LUNs are stored presented to a client over iSCSI?

No.

The iSCSI initiator (client) sees a LUN presented as a simple drive for block storage. It can't see what's really behind it, whether RAID, HDDs, SSDs, SAS, SATA, ... (I'm assuming you've created the LUN images on the RAID 6 array by "To create an iSCSI virtual disk, start the New iSCSI Virtual Disk Wizard".)

First, you need to make sure that the network connectivity is AOK (ping the target from initiator or vice versa). Add the target to the initiator. Make sure the target sees the initiator. Grant the initiator access to the desired LUN(s) in "Access servers". Check whether the initiator can mount the LUN(s).