Passive meditation are those which are not involve active movement of your body, just use our imagination, intention, watchfulness of breath and chanting etc.
The aim of all passive meditation techniques is to still the mind from wavering and distracting thoughts to gradually make pure stillness and emptiness of the mind. There are lots of passive meditation techniques which include
Zazen, Vipassana, Mindfulness, Loving-Kindness, Mantra, TM, Yoga Meditation (any type),Self-Enquiry, Guided Meditation etc.

​Osho Devavani Meditation

Devavani means the Divine Voice which moves and speaks through the meditator, who becomes an empty vessel, a channel. In the Old Testament it was termed Glossolalia. The eyes are kept closed throughout the meditation​

​Osho Nadabrahma Meditation

An ancient Tibetan Buddhist technique which was originally done in the very early hours of the morning. It is suggested that it should be done either at night before going to sleep or during the morning, when it should be followed by at least 15 minutes rest. It can be done alone with others of even at work. It is good done on an empty stomach with ayes closed otherwise the inner sound cannot go very deep​

Osho Gourishankar Meditation

Osho Gourishankar Meditation is a powerful centering technique which works on the third eye. This technique consists of four
stages of 15 minutes each. The first two stages prepare the meditator for the spontaneous experience of the third stage. Osho
has said that if the breathing is done correctly in the first stage, the meditator will feel as if on Gourishankar (Mount Everest).​