Shahbaz, now there is no  upper age limit for NEET. This means, if you meet the aggregate criteria, you will be eligible for NEET. You should have completed your 12th in Physics, Chemistry and Biology with a minimum aggregate of 50%. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST. Though you are pursuing your M.Sc now, the basic eligibility criteria that is considered is that of 12ths' alone. Now regarding your code, it will be 07. Code 07 says: Any other examination which in scope and standard (Last 02 years of 10+2 Study comprising of Physics, Chemistry and Biology/Bio-technology; which shall include practical test in these subjects) is found to be equivalent to the Intermediate Science Examination of an Indian University/Board, taking Physics, Chemistry and Biology/Biotechnology including practical tests in each of these subjects and English.