Hello aspirant, 

You haven't mentioned a category here. 

Well according to last year's cutoff you need to score a minimum of 530 to get into a government medical college in bihar if you belong to general category. Here are your options :

1.Vardhman Institute of Medical Sciences, Pawapuri, Nalanda

2.Government Medical College, Bettiah

3.Sri Krishna Medical College, Muzaffarpur

4.Anugrah Narayan Magadh Medical College, Gaya

5.Jawaharlal Nehru Medical College, Bhagalpur

6.Darbhanga Medical College, Lehriasarai

7.Indira Gandhi Institute of Medical Sciences, Sheikhpura, Patn8.Nalanda Medical College, Patna

If you belong to some reserved category then your chances may be a bit better. 

Hope it helps 

Thank you