In most BSc courses only PCM/PCB marks are to be aggregated.

Courses like BSc Zoology,Botany,Biomedical Sciences,Microbiology,Biological Sciences,marks of PCB will be preffered.

For Phycics,Chemistry,Electronics,Life Sciences,Computer Science,BSc Physical Sciences Courses PCM marks will be aggregated.

FOR Maths(hons.) And Stats(hons.) Best of 4 will be aggregated in which Maths and English is compulsory and other 2 best subjects to get the aggregated.

For more details please refer to Delhi University Broucher.