With a UR rank of 4136 and an EWS rank of 550 in BCECE, you have a good chance of securing a seat in a government medical college. Generally, EWS candidates with ranks around 500-600 have been able to secure seats in government colleges in previous years.

However, the final outcome will depend on the specific college's cutoff and the number of seats available. Keep an eye on the counseling rounds and be prepared to act quickly, as ranks can fluctuate during the admission process.