Not those who lack energy or refrain from action, but those who work without expectation of reward have attained the goal of meditation & made true renunciation.

Krishna begins the Sixth Chapter by explaining that the general people practice meditation or dhyana with the idea of ‘results of actions’ in their mind, while the advanced yogi, the true ‘sannyasi’, works without attachment. Ashtanga-yoga, a mechanical meditative practice, controls the mind and senses and focuses concentration on Paramatma (the Supersoul, the form of the Lord situated in the heart).In the dhyana yoga practice, with firm faith & determination, one should release himself from material desires and sensual pleasures, one should engage his body, mind & soul in the service of the Lord. 

Dhyana Yoga is the very subtle science of inner concentration. It turns the senses inward and helps the practitioner to achieve the state of Samadhi. According to Bhagavad Gita, Lord Krishna asked Arjuna to concentrate on God and to achieve the state of samadhi, as God has been considered as the symbol of Supreme Consciousness. The practice of Dhyana Yoga, conquer the mind over different kinds of emotions & thoughts like lust, anger, attachment, illusion and depression. provide a great sense of inner awareness & to achieve one-pointedness i.e. ekagrata.

In order to execute the process of Astanga-yoga or Dhyana Yoga by carefully controlling his mind and engaging his body, and his self in Krishna’s service, one has to live in a secluded place, and sitting on a sacred place, he has to meditate on the Paramatma (Supersoul). One should hold one’s body; neck and head erect and stare steadily at the tip of nose with an unagitated and subdued mind. One should regulate the habits of eating, sleeping, recreation and work, to free oneself from material desires. Like a lamp in the windless place, one has to steadily meditate on the Supersoul with a controlled mind. Fixing his mind on the self and on Krishna, he attains transcendental happiness in the kingdom of God.

If the mind wanders, one should bring it back under the control of the self. This continuous practice culminates into samadhi, the stage of full consciousness of Supreme. The perfection is characterized by one’s ability to see the self by the pure mind and relish and rejoice in the self. The natural boundless transcendental pleasure is the highest perfection or ultimate goal of Yoga. Even if, one abandons this process after practicing or fails, he is never at loss, he again gets a chance in a future life to start from the point where he left the process.

Lord Krishna describes the process of dhyana yoga in the sixth chapter of Bhagavad Gita as-

BG 6.11-12 : To practice yoga, one should go to a secluded place and should lay kusa grass on the ground and then cover it with a deerskin and a soft cloth. The seat should be neither too high nor too low and should be situated in a sacred place. The yogī should then sit on it very firmly and practice yoga to purify the heart by controlling his mind, senses and activities and fixing the mind on one point.

BG 6.13-14: One should hold one’s body, neck and head erect in a straight line and stare steadily at the tip of the nose. Thus, with an unagitated, subdued mind, devoid of fear, completely free from sex life, one should meditate upon Me within the heart and make Me the ultimate goal of life.

BG 6.20-23: In the stage of perfection called trance, or samādhi, one’s mind is completely restrained from material mental activities by the practice of yoga. This perfection is characterized by one’s ability to see the Self by the pure mind and to relish and rejoice in the Self. In that joyous state, one is situated in boundless transcendental happiness, realized through transcendental senses. Established thus, one never departs from the truth, and upon gaining this he thinks there is no greater gain. Being situated in such a position, one is never shaken, even in the midst of the greatest difficulty. This indeed is actual freedom from all miseries arising from material contact.

According to Gherand- Samhita, Dhyana are of 3 types

1. Sthula Dhyana: Meditation on the external physical object or on its image in chitta, our consciousness. Sthula dhyana is also an awareness of one’s body.
2. Jyotir Dhyana: ‘light’ meditation on the ukta- and mukta- triveni points, located in the area of kanda and kutashtha. During jyotir dhyana the light of Shakti and consciousness absorbs all physical aspects.
3. Sukshma (subtle) dhyana: It is a process when the subtle state of unity appears during the absorption of consciousness by light, and a yogin meditates on the tiniest point – “bindu”. It is located in the area of ajna-chakra and symbolizes the emptiness (shunya), as a matter of fact, it is Shunya. On the highest level a yogin transfers bindu to Akasha above his head.

Ultimately, these different types of Dhyana are the different manifestation of God that helps to achieve liberation. 

According to Patanjali there are 3 stages of Dhyana Practice:

1. Dhyana: The practitioner focuses on the object externally like the image of a Deity. The concentration can break in between due to thoughts, senses, and outer disturbances. In this state object and consciousness works separately.
2. Dharna: When Dhyana remains is in a continuous stream the practice turn to Dharna and the consciousness merges with the object. The practitioner has no awareness of body and surroundings and the object becomes one with consciousness.
3. Samadhi: Samadhi is the last stage where even object is also lost and the supreme consciousness remains and the practitioner left with the feeling of bliss in the state of Kaivalya.

There are different types of Dhayna Yoga or Meditation Practices that can be performed:

1. Japa Meditation
2. Sound Meditation
3. Chakras Meditation
4. Spiritual Meditation
5. Transcendental Meditation

Benefits of Dhyana Yoga:

1. Continuous practice of dhyana yoga thickened the logical center of the brain and shrinks the emotional center that improves concentration and provides the skills of problem-solving, decision making, learning, and boost emotional health.
2. Dhyana Yoga affects the pain center of the brain and improves pain tolerating ability in the human body.
3. Evidence found from many research that consistent practice of Dhyana Yoga provides the placebo effect and cure many diseases with the practice of concentration and awareness.
4. It reduces anxiety, depression, and tension as it boosts one’s emotional metabolism.
5. The longer practice of Dhyana Yoga helps one to achieve the state of liberation which is the ultimate goal of yoga.

Dhyana Yoga is not only the practice of concentration but also the practice to turn out attention inward, to the self, which is said to be the abode of God. It’s the practice of the realization of our real self, and unmanifested form of God.