Lama Tsonkhapa was invited by the then Chinese Emperor to China for the teachings of Buddhism as his fame had spread to all the parts of Tibet, China and Mongolia at that time. He could not made the trip himself but he sent Je Jamchen Choeje on his behalf to the Emperial Palace of China with a letter reporting that he could not make the trip himself but he had sent one of his most devoted and learnt disciples.

Je Jamchen Choeje's teachings became very famous in China at that time. Hundreds of Chinese disciples followed him to Tibet when he returned back to Tibet . After arriving in Tibet, he established his own monastery with his disciples and named the monastery "Gya Dratsang" (Gya for: Chinese & Dratsang for: Monastery, in Tibetan) due to the reason that he had lots of Chinese followers. 

During that time, there were four major monasteries namely Gya Dratsang, Dong Dratsang, Nyakpa Dratsang, Mey Dratsang. He grouped all the monasteries together and found Sera Thekchenling (Sera Mahayana University).
 

Kunkhen Lodroe Rinchen Senge who was also a disciple of Je Tsongkhapa founded Sera-Je after coming into exile from Drepung Monastery (Drepung Monastery is one of three great Tibetan Buddhist Universities).

After the formation of Sera-Je Monastery, Gya Dratsang became a Khangtsen or "branch institution" of Sera Je Monastery (Note: Khangtsen are sections or groups of the main Monastery where monks, speaking the same languages and same ethnic groups stay together as a community. Sera Je Monastery had 18 Khangtsens before 1959 and now only 14 are left). It came slowly to be known as "Trati Khangtsen".

"Trati" is a Sanskrit word meaning: "pioneer" or "first" for being the first Khangtsen of Sera Je Monastery. Later the pronunciation changed to Drati or Bhati; and nowadays it is officially known as "Drati Khangtsen".

Post 1959: Buxa Rehabilitation Camp:

After the completed invasion of Tibet by China in 1959, the members of all Tibetan Buddhist monasteries were rehabilitated at a special camp at "Buxa" in the state of West Bengal for the preservation of Buddhist teachings and practices which was under thread of extinction during that time.

Drati Khangtsen, which was once a large and famous Khangtsen faced great threads of its survival at that time.

Re-establishment at South India:

The monks of Sera monastery were shifted to Bylakuppe in Mysore district in the south Indian state of Karnataka in 1970. This was followed by clearing of small plots of forest areas and the construction of small houses for the monks which was sponsored by the Indian government. Drati Khangtsen also received some new monk students from some nearby Tibetan settlements, from Himalayan regions and Bhutan. The total number of the monks at Drati Khangtsen was 12 at that time. These newly arrived students became the seeds of future Drati Khangtsen.

Sources of New Students:

In Tibet, there is a traditional system by which each Khangtsen enjoys jurisdiction over a specific area of places and regions. The new studnets from these places will enter a particular Khangtsen depending upon their respective regions. Under this tradition, Drati Khangtsen also covers a large portion of areas and regions from where it receives new students.