Hello Swati, Bsc in botany from DU required you to secure at least a minimum 55% marks in the aggregate of subjects, Biology or Biotechnology, Physics and Chemistry, and 50% marks in English. This is the most basic criteria that you need to satisfy in order to apply for this course in DU. Also, you need to have passed your 12th from a recognizable board in the country. Selection is merit-based and the s election is made on the basis of merit of marks in the aggregate of three mentioned science subjects.