What forms of religion did the khmer take from india?

From India, the Khmer took the religion of Buddhism. They follow a Khmer style of Buddhism however, which is the mesh of Theravada Buddhism, Hinduism, animism and ancestor-spirit worship. This is thought to be one of the most highly synthetic versions of Buddhism. The Khmers are one of the oldest ethnic groups in Southeast Asia.

It was a combination of conquests and alliances