If you are asking about BSc Agriculture Entrance Exam then questions will be asked from Chemistry, Biology and Physics. Arihant publication books are one of the best books for preparation of BSc Hons entrance exam. They covers all the subject and also contains MCQs. Other than this, you should study NCERT. This book is available subject wisw and is really good to start with. Also solve previous year exam paper so that you can get an idea about what type of questions mostly come. Another books you can study- ICAR AIEEA UG Entrance exam guide, Bsc Agriculture entrance exam guide by Lalita Gaur.