Hello dear student, 

There is no special criteria for students to take admission in Karnataka . It's just that one student who is from general category he need to have aggregate marks more than 50% while if the student have some reservation that is he or she belongs to sc or st category then then must have 40% marks . 

Rest there is no age limit to take admission in MBBS as far as now . And also no criteria that only this year 12th passed out will get seats in MBBS . 

I hope this was helpful to you.