Hi Saeed,
Welcome to the FreeRTOS community.
We are planning to merge dev/ipv6_integration branch to main this summer. Keep a close watch.
However, we already have a RC1 (release candidate) available and the page (rc1-page) has all the details.
All the demos(including IPv4 and IPv6 WinSIM demos) are working with dev/ipv6_integartion and the above page has the details.
Can you share a few more details on the IGMP support ? Is it IGMP packet parsing, or IGMP group creation, join , leave etc. It will also be great if you can share some details on the IGMP use-case.