Hi aspirant, You have passed Xth board. You should apply KVPY SA category because KVPY SX is for XII th. For SA category, you have to secure minimum 75% (65% SC/ST) marks in aggregate in Mathematics and Science,then you are eligible for KVPY aptitude test.

For more detail : http://kvpy.iisc.ernet.in/main/eligibility.htm

• Candidates have to obtain minimum 80% marks for general category in aggregate in Science amd mathematics  in High school examinations.
• Candidates have to score at least 60% marks in aggregate in science subjects in 12th standard.