Hi Samir

As far as doing a job is considered, you will not face any problem. 

This is not a criteria of the hospital to employ doctors only if they studied from their college only. 

Which means that even if you complete your degree from Guwahati medical College, still you can apply for job openings in West Bengal government medical department.

Your selection will be based on their screening process but you are not barred from applying.

I hope it helps.

All the best!