Sinha was a professor and head of the Department of History and Archaeology at Patna University.
His guide was Lionel Barnett, and his thesis was on the topic Decline of the Kingdom of Magadh.
He also taught as a visiting professor in Bulgaria, the United States and Yugoslavia.
[2] Sinha is known for having carried out the first excavations at Vikramashila, the site of an ancient Buddhist monastery established in the 8th century CE.
[2] Sinha was among other scholars and academicians to support the Vishva Hindu Parishad (VHP, World Hindu Council) in their negotiations with the Babri Masjid Action Committee during the Ayodhya dispute.