i gave class 12 cbse board exam 2011 how?when?where?i get improvement exam form for class 12 2012 kindly plz help me.me waiting for ur reply

sir i was suffering from hernia problem.during with that problem only i had given my class 12 2011 board exam with that pain.so i want to give improvement in all subject as i am not satisfy with my marks.kindly please help me how to get improvement exam form plese help me.waiting for ur precise repl