Original sentence: In the pre-colonial era of Bengal, Baidyas were regarded as the highest Hindu castes, along with Bengali Brahmins and Kayasthas.Most Baidyas perform rituals like wearing the sacred thread.The Baidyas have generally claimed Brahmin status but some have been associated with the Ambashtha caste or sub-caste
Edited sentence: In the pre-colonial era of Bengal, Baidyas were regarded as the highest Hindu castes, along with Bengali Brahmins and upper then Kayasthas.Most Baidyas used to perform rituals like wearing the sacred thread.The Baidyas are  Brahmin  but some have been associated with the Ambashtha caste or sub-caste