@Venkatesh Naik Apologies for the delayed response, I checked with my team regarding your request to add an IPv6 address in the Reply URL and Logout URL fields in Basic SAML Configuration. Unfortunately, this scenario is not supported, and it's not possible to include an IPv6 address in the Reply URL.
However, you can submit feedback for this feature enhancement on feedback.azure.com.
Let me know if you have any further questions, feel free to post back.