There are 3 exams in India through which you can pursue MBBS and these are -NEET, AIIMS, JIPMER.

NEET - This is a national level entrance which covers 85% quota (State seats) and 15% quota (AIQ) and the minimum age to apply should be 17 years till 31st Dec if you are sitting in NEET 2018. The complete information about NEET is given below -

https://medicine.careers360.com/articles/neet

AIIMS/JIPMER - These are also the national level entrances to get admission in AIIMS and JIPMER campuses, minimum age should be 17 years. You can check the complete details for the same below as well -

https://medicine.careers360.com/articles/aiims-mbbs

https://medicine.careers360.com/articles/jipmer-mbbs

Also, if you talk about MBBS from abroad then all countries have their own eligibility and admission criteria so kindly share which country you are interested in?

Good Luck!!!