Hi Rajashree!! Kindly mention the exam you are talking about here. Still let me give you thee details of some examinations. If you get this score in your boards paper, then you are definetily going to fail and you will have to give a retest. If you are talking about competitive exams like JEE, then it depends on your total score even if you have got 15 marks in physics and maths and till you managed to get an over all passing marks then you will be declared pass.