Hello Pooja,
Bachelor of Science is a 3 year undergraduate degree program offered after class 12th. The admission to BSc is done in the first year of the course through entrance exam or direct admission in private colleges. There is no provision for taking admission directly second year of BSc or any degree program except for the lateral entry programs in which students are admitted directly into the second year after meeting the specific eligibility criteria for the same. But there is no lateral entry for admissions into 2nd year of BSc, so you won't be able to get direct admission in 2nd year. In order to pursue your Bachelor's of Science, you will have to take admission in first year only.
Let me know if you have any other questions.
Thank you!
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