How to remove this user completely from adobe analytics account? As you can see I removed access to product (marked in green) why it is still shown as active? How to remove it?
The "account" is technically still active because you aren't really changing the account itself, you are just removing roles and permissions at this point.
The user based on your screenshot will not have access to Analytics... but their account still exists.
To remove them from your user lists, in the main user list... there are checkboxes next to users names... once you check at least one user (you can also select multiple), a new option appears to remove the user(s):
Remember to also remove this user from your Analytics interface: Admin > Analytics Users and Assets. This is also the place to transfer assets (projects, segments, calculated metrics, etc) from one user to another. This is useful for ensuring that the assets created by your deleted user can still be managed by someone else.