To be eligible for NEET, you should have completed your 12th, passed in all subjects and secure a minimum aggregate of 50% in Physics, Chemistry and Biology. Now when we say in Passed in All subjects, if Mathematics has been your Additional subject and doesn't show up in your 12th Marks sheet, then you are fine, But if Mathematics is also a part of your Marks sheet, you should mandatorily pass the subject. You should pass in all subjects that appear in your Marks sheet irrespective of the factor whether their marks are calculated for NEET or not. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST.