Out of the 243 seats in Bihar legislature, his party, the Janata Dal United or JD(U), has 118 legislators, and to prove the majority of JD(U), 122 votes are required.
According to reports, four of Bihar's six independent legislators have reportedly committed to support the JD(U).
The BJP in Bihar with its 91 legislators will reportedly vote against Nitish.
Former chief minister and Rashtriya Janata Dal (RJD) chief Lalu Prasad Yadav has also confirmed that the 22 legislators from his party will vote against the chief minister, said reports.
The Congress is likely to either vote in favour of Kumar's government or abstain from voting, NDTV citing sources reported.
The JD(U) announced its decision to end its ties with the BJP on Sunday, ending a 17-year-old alliance and drawing clearer battle lines ahead of national elections less than a year away.
The ties ended over the projection of Gujarat Chief Minister Narendra Modi, a BJP strongman seen by many as somewhat a divisive leader, as the face of the National Democratic Alliance (NDA) in the 2014 general elections.
Kumar's government in Bihar will now have to face a trust vote in the state legislature, scheduled on Wednesday, to prove a majority.
--IBNS (Posted on 19-06-2013)