Right now there is no upper age limit for appearing for NEET. This is important because NEET is the only entrance examination for admission to Medical, Dental, Ayush and Veterinary courses across India. Even to study MBBS abroad, it is mandatory to qualify in NEET. So even if you have completed your 12th in 2015 but have secured a minimum aggregate of 50% in Physics, Chemistry and Biology, then you are eligible for NEET. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST. If you fulfil this criteria, you can appear for NEET and should you qualify in NEET,, you can certainly study MBBS abroad.