as mentioned in the epic Mahabharata Tvaṣṭr or the Rathakāra is Śukrācārya's son, Śukrācārya is Bhṛgu's grandson and Vāruṇibhṛgu's son. These Rathakāras were called Brahmins, expert in the architectural lore, and were engaged in making what is called Brahmayāgādi, the making of sacrificial implements, statues, production of royal crowns and thrones, gold chariot or Ratha which were necessary for many of the sacrifices. Many hymns are found in the Vedas praising the Ratha and the Rathakāra. Some Purāṇas identify them with Viśvakarman. As mentioned in the texts like Skanda purāṇa and Padma purāṇa, Tvashtra praised as Rathakāra is mentioned to have married sage Jaiminī's daughter Candrikā. The Vāyu purāṇa and the Matsya purāṇa mentioned him as belonging to the Bhṛgus. Niṣādapati According to Hiraṇyakeśisutra by Yajñavalkya, a son begotten to a Niṣāda lady by a Brahmin was called as Niṣāda Rathakāra and was considered as Anārya or non aryan. If daughter of this Rathakāra is again married to a Brahmin and their daughter is married to a Brahmin, and a daughter born to them again married to a Brahmin, and so on till seven generations, then the son of the seventh Niṣāda Rathakāra's daughter attains brahminhood. The uplifted Niṣādapati and his progeny were entitled to perform the sacrifices and even the Brahmayāgādi. This Rathakāra's ways of earning a livelihood are stated as comprising chariots, carts and the like. Rathakāra in the Atharvaveda This systems regards the Rathakāra as an offspring of Māhiṣya, or the son of Kṣtriya husband and Vaiśya and Karaṇi or the daughter of Vaiśya husband and Śudra wife. Although such an origin cannot be considered as accurate historically. Other scriptures Other texts like Bṛhajjātiviveka and seers like Baudhāyana, Vijñāneśvara have mentioned many Rathakāras of mixed origin and having varying social status. According to some doctrines these Rathakāras have no right to take part in any of the sacrifices as they are degraded to Śudra. A Śudra is not initiated to Vedic studies hence no Upanayana, as the sacrificer has to know Vedas, hence Śudra cannot participate in any kind of Yajña. Baudhāyana on the other hand admits this degraded Rathakāra to the ceremony of Upanayana, according to him fallen Rathakāra ought to perform this ceremony the rainy season. But some text mention that even a Śudra was allowed to participate in few sacrifices, and was even entitled to perform certain sacrifices like Pākayajñas, Śradhayajñas. But they were