Das is a common last name in South Asia, among adherents of Hinduism and Sikhism, as well as those who converted to Islam or Christianity.
In Bihar, it is used by people belonging to Ambashtha and Karn Kayastha castes.
[5] More broadly, in Bengal, Bihar, and Jharkhand, the surname "Das" is also used by the Dhobi and Patni communities.
[6] In Assam, the Kaibarta, the Patni, the Koch-Rajbanshi, and other communities also use Das as their surname.
[7][8][6] In Odisha, the Das surname is used by the Gopal and Karan castes, while "Dash" is used by the Brahmins.