In 6th edition, all models may attempt a Deny the Witch saving throw against hostile psychic powers and sorcery.
Please remember that you're not playing 5th anymore and don't need a psychic hood, or anything similar, to attempt Deny the Witch. Sure, its not likely to succeed most of the time, but you might as well roll the attempt and see what happens. :-)
Oh -- and don't forget the bonus if you have a Witch of your own that is superior in Mastery Level to the incoming hostile psychic power caster.