MyBB Community Forums

is there any idea or method that only the admin and supermoderator or admin team can post html in posts....

By default there is one option in ACP that whether you want to use html in posts or not ? if yes then which in forum.

No, the allow html in post is forum specific, not a user setting.
You'll probably have to allow html on forums and create a short plugin to deny it from non allowed users. But you may have a trouble with quoted messages.