What is "bharatas"

Bhāratas were a tribe mentioned in the Rigveda, especially in Mandala 3 attributed to the Bharata sage Vishvamitra. In the " river hymn" RV 3.33, the entire Bharata rulers are described as crossing a river Yamuna. Bharatá is also used as a name of Agni (literally, "to be maintained", viz. the fire having to be kept alive by the care of men), and as a name of Rudra in RV 2.36.8.

Mandala 7 (7.18 etc.) mentions the Bharatas as taking part in the Battle of the Ten Kings, where they are on the winning side. Due to the victory of the Bharata chieftain Sudas in this battle, the Bharata rulers were able to settle in the Kurukshetra area. They appear to have been successful in the early power-struggles between the various Vedic tribes so that in post-Vedic ( Epic) tradition, the Mahābhārata, the eponymous ancestor becomes Emperor Bharata, the ancient conqueror of all of India, and his ruler and kingdom is called Bhārata. The Bharata ruler later allied and merged with the Puru ruler, to form the Kuru ruler.

The etymological root of Bhāratas is the same the official name of India "Bharat".