Hey
Here is a list of various government medical colleges in Bihar and their respective cut offs for admission in the previous year under the State quota for the SC category. Hence you would require a score above 380 atleast for a fair chance of admission here.
Jawaharlal Nehru Medical College, Bhagalpur
90,979

385
Nalanda Medical College, Patna
69,414

415
Government Medical College, Bettiah
94,255

381
Vardhman Institute of Medical Sciences, Pawapuri, Nalanda
91,877

384
Indira Gandhi Institute of Medical Sciences, Sheikhpura, Patna
68,311

417
Anugrah Narayan Magadh Medical College, Gaya
85,948

391
Sri Krishna Medical College, Muzaffarpur
84,196

394
Patna Medical College, Patna
49,939

447
Darbhanga Medical College, Laheriasarai

69,347

415

Hello Aakash
To get admission in a government college, your NEET score should be minimum 450+ (if you're applying for 85% state quota) and 590-600+ (for 15% AIQ seats).
As the cutoff changes every year and so the safe marks range can't be predicted- also category wise.
So keep high target and prepare accordingly. The cutoff for the government colleges goes high maximum times and so the competition is tough.
Hope you're getting my point.!
Prepare well and study smart.! Practice maximum to school maximum.!
Good Luck.!!