More than 5.32 lakh voters across 30 districts will decide the fate of candidates in four Graduates and four Teachers constituencies.
The NDA is seeking to retain its existing seats, while a JD(U) rift over the Patna Graduates constituency has complicated its prospects.
Jan Suraaj is contesting all eight seats in its first major electoral test, while the RJD and Congress have defended their decision not to field joint candidates.