When you are under hypnosis, you generally remain in control of yourself. Hypnosis is a state of focused attention and increased suggestibility, but it does not mean you lose control over your actions or decisions. You cannot be made to do anything against your will or moral beliefs. You will typically be aware of what is happening and can choose to accept or reject suggestions. If at any point you feel uncomfortable, you can usually come out of the hypnotic state.
In summary:
You remain aware and conscious.
You keep control over your actions.
You can't be forced to do something against your will.
Hypnosis is a cooperative process between you and the hypnotist.