I am doing some research on what is available on IPv6 DHCP. It seems like only SLAAC and IPv6 with Prefix delegation is supported in the latest ROS7. Is this correct?
Correct, SLAAC and DHCPv6 including Prefix Delegation is supported.
What else do you need?
When acting as a DHCPv6 client, ROS 7 can also request an address for itself from an external DHCPv6 server, even together with the prefix.
DHCPv6 server can serve options when SLAACs other-configuration is enabled.
DHCPv6 Relay to handle routing information would be nice.