Which two language groups are primarily spoken by tribals in India?

The correct answer is Option (4) → Austric and Tibeto-Burman

Option (1) Tibeto-Burman and Indo-Aryan — Incorrect. Tibeto-Burman is mainly a tribal language group, but Indo-Aryan is shared with the rest of India. Tribals form only about 1% of Indo-Aryan speakers.

Option (2) Indo-Aryan and Dravidian — Incorrect. These two groups are shared by the rest of the Indian population. Tribals form only about 1% of the first and about 3% of the second.

Option (3) Austric and Dravidian — Incorrect. Austric is spoken by tribals, but Dravidian is shared with the wider population. Tribals form only about 3% of Dravidian speakers.

Option (4) Austric and Tibeto-Burman — Correct. Austric and Tibeto-Burman are primarily spoken by tribals. Tribals account for all Austric speakers and over 80% of Tibeto-Burman speakers.