Hii Yash!
It's better not to think like that. Why to fail? Do a little hard work behind the subject and you are good  to go. Although, if you fail even in one subject, you need to give the repeat of it later. If you have to apply for any entrance exam you need to satisfy the minimum eligibility criteria. The criteria in general is usually passing class 12th with minimum 50% marks. So, you need to pass in each subject. For exams such as NEET, Jee Mains etc., The individual percentage or combined Percentage of the subjects are asked. You may be eligible there, but why to take chance. Study well and pass in each subject.
Hope you understand.
Good luck!

If you dont fail in the basic compulsory subjects like physics, chemistry, mathematics and biology ,only best of five is considered. So if you fail in library and information science subject if wont affect you much.you will still remain pass in overall context