NDTV Explains: With Eye On Polls, Breaking Down Bihar's Caste Survey

The data - coming months before next year's Lok Sabha poll - underlines the electoral importance of OBCs and marginalised communities - both for the BJP, which has opposed calls for a national caste census, and the opposition.

The Bihar government on Monday released data from a controversial caste-based survey that said nearly 63.1 per cent of the state's 13.1 crore population belong to backward classes and nearly 85 per cent belong to either a backward or extremely backward class, or a Scheduled Caste / Tribe.

Specifically, 36 per cent of the state is from an extremely backward class, 27.1 per cent is from a backward class, 19.7 per cent is from a Scheduled Caste and 1.7 per cent is from a Scheduled Tribe. The general category, including so-called upper castes, account for 15.5 per cent.

The report also underlines the minority status of those who identify as Muslims in Bihar; they constitute less than 18 per cent of the population while those who identify as Hindus account for 82 per cent. In the 2011 Census these numbers were 16.9 per cent and 82.7 per cent, respectively.

A deep-dive shows the Yadav community - the group to which Deputy Chief Minister Tejashwi Yadav belongs - is the largest sub-group, accounting for 14.27 per cent of all OBC categories.