Hi Aspirant!

The certificate for any undergraduation degree is provided after the completion of the course (3 or 4 years) without any backlogs. As you mentioned that your elder sister is in BSc 2nd year and BSc is a 3 years undergraduation course, so she will get the degree certificate after completing of 3rd year exams. But if she quits the degree or get failed in 3rd year then she will not get the degree certificate until unless she qualifies all the exams.

Thankyou!