According to the Ethnologue, there are 36 indigenous living linguistic communities, which include 17 Sino-Tibetan, 10 Indo-European, 7 Austro-Asiatic and 2 Dravidian language-speaking groups.
[5] Vast number of ethnic tribes of Bangladesh are traditionally Buddhists and Hindus by faith while others are largely Christians and small animists.
The government of Bangladesh has referred to the Chittagong Hill Tracts' small ethnic groups as such, rather than indigenous people.
Their cultural traits are connected to their ancestral heritage, including dress (which is called thumbui—the lower part, and angi—the upper part), food (mostly spicy, sour, and hot), writing (Burmese script), traditional songs and musical instruments (for example, kappya, jjea, and kharra).
The Tripuris are one of the major ethnic community living both in the plains and the Chittagong Hill Tracts in Bangladesh.
The Mru people (also Mro and Moorang) are considered the original inhabitants of the Chittagong Hills where they migrated from Arakan of Burma from the 14th–15th century.
They have actively participated in the Tebhaga movement led by Ila Mitra in 1950, the Santal revolt, Birsa Munda Uprising, Kol revolt, Jitu Samur Rebellion, Pandu Raja Insurgency, Swadeshi Movement and the War of Liberation in 1971.
The Santal women wear coarse homespun cotton sarees of bright colours that barely reach their knees, while the upper end is flung over the shoulders.
There is practically no furniture except a wooden bedstead and bamboo machang on which the people of the comparatively well-to-do class spread their beds.
Although the Santals used to lead a prosperous and peaceful life in the past, their economic and social conditions are now very backward.
Particularly significant in this regard was a Welsh missionary, Thomas Jones, who transcribed the Khasi language into Roman Script.
A substantial minority of the Khasi people follow their tribal religion; called variously, Ka Niam Khasi and Ka Niam Tre in the Jaintia region and within that indigenous religious belief the rooster is sacrificed as a substitute for man, it being thought that the rooster "bears the sins of the man and by its sacrifice, man will obtain redemption"[15] (compare Kapparot).
The main crops produced by the Khasi people living in the War areas, including Bangladesh, are betel leaf, areca nut and oranges.
Jaintia, an ethnic group living in Sylhet region and also known as Synteng or Pnar, have a very rich tradition and political history.
According to the Anthropologists, Jaintia is one of the ancient original groups who migrated to the North Eastern region of the sub-continent and settled down there.
The literacy rate of the Jaintia is 80%, the highest among all tribes living in greater Sylhet region.
But the Jaintia ladies wear another piece of cloth as a modesty scarf knotted on the shoulder like Khasi women.
The Jaintia society is divided into a number of tribes, such as Sarty, Nayang, Kayang, Lanong, yangyoung, rymbai, dkhar etc.
In spite of the existence of tribal system in the Jaintia society, caste discrimination is totally absent there.
Thus the human beings became busy with their families and worldly affairs so much that they started forgetting God gradually as the relationship weakens.
They migrated to Bangladesh during the reign of Manipuri king Rajarshi Bhagyachandra (Meitei: Ching-Thang Khomba) (1764–1789) and the process was accelerated by the Manipuri-Burma war.
During that period, King Chourajit Singh accompanied by a large following of Manipuri subjects moved to areas – now in Bangladesh.
Manipuri culture has a rich and colourful tradition where dance and music play a vital role.
A very popular festival of the Manipuris is a type of Gopi dance celebrating the romantic liaison of Radha and Krishna.
A Manipuri bride comes to visit her parents for the first time on the fifth day after marriage, providing an occasion for a lavish feast.
According to traditional custom, all members of the clan are invited to this ceremony and they come with presents of rice, fish, fowls, money.
After disposing of the body, the pallbearers take a bath and dry their hands by holding them above a fire before entering their house.
The Hajongs community lives mostly in the Mymensingh and Sylhet districts of Bangladesh and are predominantly rice farmers.
The Keot (Kaibarta) people of Bangladesh belong to the Austric stock and are an aboriginal tribe which has slowly been converted into a caste.
They have lost their mother tongue and use the standard language of Bangladesh for communication but they have still preserved their cultural, racial and traditional identity alive.