Hi.

Deriving from a similar answered question. Karnataka Board offers improvement in examination. However, for that you need to reject your current PUC Result and then you have to re-appear in examination held with current 12th examination. Practical marks will be carried forward. Supplementary exams are only for students who have failed an examination subject. For more queries please visit this official website (http://pue.kar.nic.in/pue/support_html/examination.htm) .

If you have a further specific query please feel free to comment.

Best of Luck.