when I get 350 marks in neet UG can I get government college for mbbs

Hi
Congratulations on qualifying the exam. Since you have not mentioned what category you belong to and what state quota is applicable to you it's a bit difficult to tell. However, at this score I highly doubt you'll get a seat in a government medical/dental college. You can look for admission in private medical/dental colleges.
You can predict your NEET All India Rank using our rank predictor. Link for which is given below:
https://medicine.careers360.com/neet-rank-predictor?utm_source=qna&utm_medium=neet_rp
You can also predict your college using the predicted rank through our college predictor with the following link.
https://medicine.careers360.com/neet-college-predictor?utm_source=qna&utm_medium=neet_cp

You might also want to get enrolled in BAMS/BHMS courses as these are professional courses certified by our medical council.
BAMS - Bachelor of Ayurvedic medicine and surgery. It is a 5.5 years long course including 1 year of compulsory internship. You get to study about the most ancient medical practices of our country i.e Ayurveda.
BHMS- Bachelor of homeopathic medicine and surgery. It is a 5.5 years long course including 1 year of compulsory internship. You get to study about the homeopathic aspect of medicine.

Hope this helps
All the best!