I am using owin authentication but not able to set the same site cookie to NONE for ajs_user_id and ajs-anonymoususer_id
I have tried using web config to set it . but its not working
To set a samesite cookie with none, then it also must be set with the secure attribute, and you must do this over HTTPS, not HTTP.
To complement this answer, I wrote a blog post that goes into more detail about this topic: Debugging cookie problems