I am sorry to tell you but to get a government mbbbs college or institute, the usual cutoff rank is around 5800 which means a score above 512. As your score isn't near or above the usual cutoff, I think it's not possible. Even for sc/st category, it is required above 360. But don't lose hope! You can try college predictor of careers 360 for medical colleges and institutes which can offer you a seat.