Learned Mr.Kameswarao has given valuable advice. Kindly follow it.
You have been able to secure admission in the premier and reputed institute of the country, which has conducted some of the landmark research and produced one of the very bets doctors. Once in the institute you may take a call and may decide of super specialization e.g. DM/M.ch, and even further. You shall get opportunities and exposure for furthering your career, and thus may get remuneration beyond expectation.
The job offered to you is as per your current qualification. You may enquire about the education policy of the employer. There may be a scope of study leave, sponsorship etc after a stipulated time. And accordingly you may still be eligible to appear for the entrance exam after the number of years as specified in policy of the prospective employer. Like this time, you may be able to crack the entrance time again. Keep preparing.
Please assess all options and take a qualified decision.