I mean does one have to go into deep states of meditation like in a trance in mysticism?
Thanks for the clarification. I can't answer for all mystics, but it's my view that the heart of mysticism,
The Mystical Experience itself, is an experience, as opposed to a mere body of knowledge. And that experience seems to be something beyond a mere trance.
During a trance, one's normal, every-day consciousness is still intact, albeit altered a bit. But during the mystical experience, one's normal, every-day consciousness comes to an abrupt end. It is replaced by a kind of awareness that is not based on, or grounded in, a distinction between oneself and what oneself is aware of.
So, to more directly answer your question. Yes, there is a sense in which one must go into "deep states of meditation" in mysticism. That is, there is no substituting knowledge for the mystical experience itself.