Dear Tharanish, MCI stands for Medical Council of India. This is the authoritative body for Medical Professionals across India. Now it is being overtaken by NMC which is National Medical Commission/Council. Now for you to be eligible for getting a MCI eligibility certificate, you should fulfil their criteria which is you should have completed your MBBS along with your 1 year mandatory internship. With 10+2, you are eligible to study MBBS but not eligible for getting a MCI eligibility certificate.