Complex sentence: The Indo-Aryan tribes mentioned in the Rigveda are described as semi-nomadic pastoralists, subdivided into temporary settlements ("vish ", viś) and headed by a tribal chief ("raja", rājan) assisted by a priestly caste.
Split into simpler sentences: The Indo-Aryan tribes mentioned in the Rigveda are described as semi-nomadic pastoralists; when not on the move, they were subdivided into temporary settlements ("vish ", viś). They were headed by a tribal chief ("raja", rājan) assisted by a priestly caste.