Green Tara Buddha is almost certainly one of the most popular Yidams in Vajrayana Buddhism. In Tibetan Buddhism especially, Green Tara is accessible to all, Mother of all the Buddhas, and virtually a “universal” symbol of Active Compassionate Wisdom. Green Tara, who is also a Savior Goddess, is as accessible to the prisoner in jail as to the most benevolent of monks — she is Universal and open to all. With her right leg outstretched, ready to leap to our aid, she is among the most approachable of Buddhist deities.
But many people don’t realize she has a “Highest Yoga Tantra” aspect called Chittamani Tara (translates as “Mind Jewel Tara”) — a profound “two stages” practice.
There is a saying in Tibet, “All men are Chenrezig, and all women are Tara.” This isn’t a light turn of phrase. The Oneness of phenomenon is expressed in this phrase, together with many other profound concepts.
During Chittamani Retreat teachings H.E. Zasep Rinpoche explained the concept of Tara teaching universally to all levels of student:
“Tara is everywhere. Tara is in the pure lands. Tara is here also. Why is Tara in the pure lands? Tara is in the pure lands to teach to the Bodhisattvas, the highly realized beings… Then, Tara comes down to us, many aspects of Tara — 21 Taras and so on — and there are other aspects of Tara, like Vajrayogini, Palden Lhamo, and so on and so on. Tara comes to us as deities, as Dharma protectors — so Tara is here, now.” 
Tara for all levels of practice
She also appeals to all needs and levels of practice. No initiation is needed to chant her mantra — even the most casual of admirers can benefit from her practice:
Om Tare Tuttare Ture Soha
Yet Tara also has a Highest Yoga Tantra aspect known as Chittamani Tara (sometimes spelled Cittamani, but pronounced ‘ch’.) Visually, aside from two blue uptala (night lotus) flowers in full bloom, she appears to be Green Tara. (Green Tara typically has one fully open uptala in left hand (also called blue night lotus) flower — and, in some visualizations, one which is “about to open”. Cittamani Tara has two fully open blue uptala flowers. (Sometimes, as in Khadiravani Tara — Tara of the Khadira Forest — she also has two uptala flowers.) She is described as:
“Chittamani Tara, the transcendental deity of emerald colour, with her right hand in the gesture of supreme generosity, and her left, at her heart, in the gesture of bestowing refuge in the three jewels. Each hand holds the stem of an utpala flower. She is beautifully adorned with silks and precious ornaments, seated in the centre of an aura of light with right leg extended and left drawn in. In her heart a green TAM radiates light.”
All Taras are one — even though some of the 21 Taras have multiple arms, attributes, gestures, and colours. Gelek Rimpoche, in his “Cittamani Tara Extensive Commentary” said:
“I want you to remember the two legs of the Vajrayana, the relative and the absolute. Whether white, green, yellow, red, dark blue or multicolored, all Taras are Tara, yet each different manifestation does have some particular responsibilities, some special thing. In absolute reality, however, they are all one Tara: the activities of the enlightened beings… In that way Tara is said to be the total activity of the enlightened beings. Their activities have become a being, and that being pops up as the physical form of Tara. In the same way Avalokitesvara is the compassion of all enlightened beings and Manjushri is their wisdom. ” 
Tara’s forms are endless. Where there is a need, there is her emanation. Gelek Rinpoche continues:
“To make a long story short, by about this time Tara manifested so many manifestations everywhere, particularly the Twenty-One Taras and the One hundred thousand Taras. The Twenty-One Tara manifestation is very meaningful. When Tara came out of Avalokitesvara’s heart as a helper, a handy-person to all the Buddhas, this handy-person then created another handy-person, who again created another handyperson. All these big manifestations came about at that moment, particularly the White Tara for longevity. Also Rigjema, used for power. Then there is Yangchenma, who is Saraswati in Sanskrit. She is special for literature and language. All these are manifestations of Tara. Even the wrathful protector, Palden Lhamo, is a manifestation of Tara. In that case she is not a yidam but a protector. Palden Lhamo also manifested at that time.”
Chittamani Tara Highest Tantra emanation
Chittamani Tara is a Highest Yoga Tantra practice (maha anu yoga) of Tara. This does not mean She is a “higher deity” — the Boss Tara. She is still Tara. Tara is always Tara. The Enlightened Mind has no limitations in terms of form. Here, with Chittamani Tara, the form is similar to regular Green Tara — the main difference is only in the practice, and the twin blue uptabla flowers visualized (instead of the single with Green Tara). There are 21 Taras, and 108 Taras for a reason — there are that many ways to practice, and more. There are even other Higher Tantric forms of Tara, including Vajrayogini.
Yet, Chittamani Tara is the “Highest Yoga” Tara from the point of view of Tantric practice as Green Tara. (Not to be confused with Cintamani Tara “Wish-fulfilling” golden Tara.)
Gelek Rimpoche quotes the root text: ” In the root text Tara herself says,
‘According to your wish I will explain how to practice the Tara tantra in the system of maha anu yoga tantra’. Although normally Tara belongs to kriya tantra, this tantra is made into maha anu yoga by Tara herself. And of course, in this particular case, there are many continuing activities through teachings, initiations, and oral transmissions.”  Here, Tara was speaking to the great Gelugpa Yogi Takpuwa Dorje Chang.
Maha Anu Yoga Tantra
All schools of Tantric Buddhism have forms of higher yogic practices. In the newer schools (such as Gelug) the highest tantras are Annuttaratantra (or Maha Anu Yoga) — which is associated also with Mahamudra. Highest Yoga Deity Practices in Gelugpa include:
What is Highest Yoga Tantra? Maha Anu Yoga includes both development and completion practices, and are a “full path” to enlightenment, meant for senior practitioners — and only given by permission and empowerment. Translated Annuttarayoga means “Unexcelled Union Continuity.” These practices include subtle body yogas, with a much more involved practice aiming at complete personal transformation and realizations. They also carry a heavier commitment. It is assumed that anyone taking on Highest Yoga Tantric practices is very experienced and focused on serious progress on the path to realizations.
Source of the Chittamani teaching
Tara Herself gave the practice of Chittamani Tara to Mahasiddha Takpuwa Dorje Chang. The practice is the best known of the rarely taught “13 initiations from the Clear Vision of Gelugpa Yogi Takpuwa Dorje Chang” in the 19th century. Is this the same Tara we know and love? Yes, she’s still Green Tara, albeit a Tara who gifted us with a complete Highest Yoga Tantra practice cycle.
Chittamani Tara is a main practice of many of history’s great Gelug teachers, including Pabongkha Rinpoche (who wrote the most authoritative and widely-respected commentary: see inset photo), H.H. Trijang Rinpoche (tutor of the current Dalai Lama), and H.H. Zong Rinpoche. Today, relatively few Lamas transmit the precious empowerments and teachings.
For serious practitioners, who adore Green Tara, Chittamani Tara is a much sought-after teaching and practice — although the practice commitment is at a higher level in terms of time and sincerity. As a Highest Yoga Tantra practice, it includes all stages of practice: Development and Completion. It includes a unique and profound “body mandala.”
It is not acceptable to practice Chittamani Tara practice, despite her otherwise famous accessibility to all, without permission, teaching and empowerment of a qualified Guru of lineage. This is because the practices should not be attempted by those who have not received teachings.
For those not yet ready for Higher Yogic practices, Green Tara is ready in many other forms — especially 21 Taras. Chanting the 21 Praise of Tara daily is for everyone — and helps bring Her energy and blessings into your life.
 Cittamani Tara 2011, Nelson Gaden for the West retreat with H.E. Zasep Tulku Rinpoche
 Cittamani Tara Extensive Commentary, Gelek Rimpoche of Jewel Heart