Kusum, yes you can pursue a Diploma course and a B.Sc course. According to UGC rules, you can pursue 2 courses at the same time given one of them is through Distance mode and one of them is through Regular mode. So for example, lets say you want to study both Diploma and B.Sc at the same time. What you can do is join Diploma through Distance education on the basis of your 12th qualification and join B.Sc through regular mode. If the University you want to join your B.Sc also offers Distance education courses, you can join Diploma course from the same University. But you cannot take up Diploma and B.Sc both through Regular mode. UGC rules do not approve of the same. So you can take up Diploma through Distance mode and B.Sc through Regular mode both from the same University or different Universities.