There is no function programmed to allow someone to read a forum but not post in it. A ban is complete, or nothing at all. So in terms of technical restrictions, no you can't.
You could try talking to the Moderator who banned you, and seeing if they'll take a promise, but don't hold your breath on that.
____________"May the Grace of Ara go with you, and His Vengeance be wrought upon your enemies."
Only fools and children dream of heroes.