Buddha gave up yoga after practicing it for six years. He saw it could not yield truth.+

Let carefully noted that the yogic Samadhi is nothing but a long trance, is not Self-awareness. 

Although the ego becomes still for some time, people generally overestimate their feeling and sensation, and a yogic Samadhi is invariably supposed to be Self-realization. 

The yogic Samadhi is a temporary state; as soon as the yogi comes out of it,  he becomes aware of the duality and reminisces again in the grip of ignorance. Thus,  the yogic Samadhi will not eradicate ignorance. 

 The yogic Samadhi is experienced by you. You are the false self within the false experience. Thus,  the yogic Samadhi can never take one beyond the experience of the form, time,  and space.  

Self-realization is the realization of the truth that is beyond form, time, and space.  

Self-realization is only gained through acquiring Self-knowledge or Brahma Gnana or Atma Gnana.  Only through Self-knowledge or Brahma Gnana or Atma Gnana, the Soul transcends the limits of form, time, and space and becomes free from experiencing the dualistic illusion as a reality.  Thus, it is only in the realm of the Soul that the mind becomes one with the Soul, the Self.

Panchadasi: ~ the impossibility of yoga arriving at a successful end to its practices.  P.509 v, 109

The ‘Self-realization' through yoga is not philosophic. Every yogi who shuts himself in a cave is not thereby freed from thinking.  

Yoga can lead only to temporary peace because the world is subject to change. Only Self-knowledge or Brahma Gnana or Atma Gnana can yield Advaitic awareness in the midst of the form, time, and space.  

Buddha gave up yoga after practicing it for six years. He saw it could not yield truth. 

Buddha gave up his austerities of yoga as impossible and useless. Thus,  Buddha got enlightenment only after he gave up Yoga. (Page.70/71 "Buddhism In Translation” by Warren)

Unless one exercise his Buddhi--reason--there is no chance of getting the ultimate truth or Brahman

Buddhism has not proved the truth of Nonduality. Buddha pointed out the unreality of the world, we agree. He told people they were foolish to cling to it. But he stopped there. He came nearest to Vedanta in speech but not to Vedanta fully. 

Only when we independently search for the truth without religion and its doctrine,  then we will be able to realize the truth beyond form, time, and space. :~Santthosh Kumaar