Dear Nafisha, you managed to pass in rest of the subjects and that is a good thing. Now you scored less and you failed in one subject. You cannot go back in time and undo anything. What you have in hand at your disposal is the present and the future. If there is a provision of supplementary exams, please reappear and clear this exam this year without keeping it in pending for too  long. Now this will not affect your future in any way. If you can manage to pull yourself together for the next 2 years and score a good aggregate, you can get a good college if you want to pursue PG or you can also get placed in a decent company. So, set yourself a goal that this is the last time you will ever fail a subject, promise yourself that and move ahead. Good luck!