The state religion of Bhutan is the Drukpa sect of Kargyupa, a branch of Mahayana Buddhism. Ever since its introduction in the eighth century, Buddhism has shaped the nation’s history and played a vital part in the life of its people. Throughout Bhutan, from the most densely populated valleys to the most remote mountain way-stops, religious monuments and symbols bear witness to a deep and respected faith. One comes across prayer wheels, prayer flags and the sacred mantra Om Mani Padme Hung carved on stone slabs and rocky hillsides. Chortens (Stupas) housing the sacred relics dot the landscape. Goenpas (Monasteries) and Lhakhangs (Temples), some dating back to as early as the eighth century, are the focal point of each village. Bhutanese arts are deeply imbued with a strong sense of morality, with many art forms epitomising the eternal struggle between forces of good and evil.

  Buddhism

The Ngalop people, descendants of Tibetan immigrants, comprise the majority of the population in the western and central areas and mostly follow the Drukpa Lineage of Kagyu Vajrayana.
The Sharchops, descendants of the country's probable original inhabitants, live in the east. Reportedly, some Sharchops practice Buddhism combined with elements of Bon whereas others practice animism and Hinduism. Several Sharchops hold high positions in the government, the National Assembly, and the court system.
The government supports both Kagyu and Nyingma Buddhist monasteries. The royal family practices a combination of Nyingma and Kagyu Buddhism and many citizens believe in the concept of "Kanyin-Zungdrel," meaning "Kagyupa and Ningmapa as one."

  Hinduism

Hindus, mainly in the South, practice Hinduism. The very first Hindu temple was constructed in Thimphu in 2012 by His Holiness The Je Khenpo, Chief Abbot of Bhutan, and Hindus practice their religion in small to medium-sized groups. Hinduism is more common among the Lhotshampa ethnic group, although a fair amount of ethnic Lhotshampa also follow Buddhism as well.

  Bön

Bon, the country's animist and shamanistic belief system, revolves around the worship of nature and predates Buddhism. Although Bön priests often officiate and include Bön rituals in Buddhist festivals, very few citizens adhere exclusively to this religious group.

  Christianity

Christians are present in small numbers, especially in the Nepalese ethnic group. According to a 2007 report there were no Christian missionaries in the country, although international Christian relief organizations and Roman Catholic Jesuit priests engaged in education and humanitarian activities. Christianity was first brought to Bhutan in the late 17th century by Portuguese Jesuits, but the teachings failed to gain much traction among the devout Buddhists of the Bhutanese people. More recently (2014) Christian ministers are being arrested for spreading their religion.

  Islam

0.2% of the population of Bhutan is Muslim. In 2010, the Pew Research Center estimated that 0.2% of the population were Muslims.

  Freedom and regulation of religion

The law provides for freedom of religion; the religious institutions and personalities have a duty "to promote the spiritual heritage of the country while also ensuring that religion remains separate from politics" and that religious institutions and personalities remain "above politics." Reflecting the government's stated purpose of preserving individuals' religious and cultural values, the above prohibitive clauses in the Constitution have been interpreted to apply to proselytism and to prohibit religious personalities from voting, respectively.
The Religious Organizations Act of 2007 aims to protect and preserve the spiritual heritage of Bhutan through providing for the registration and administration of religious organizations. To meet those goals, the Act creates the Chhoedey Lhentshog as the regulatory authority on religious organizations. This body regulates, monitors, and keeps records on all religious organizations in Bhutan, which are in turn required to register and maintain specified corporate formalities.
Through 2007, there were no reports of violence associated with pressure to conform to Vajrayana beliefs. There were no reports of societal abuse or discrimination based on religious belief or practice.

Information Taken From The Google.