BSc BCom Hons is a 3 years undergraduate course in Delhi University.in Delhi University for bcom honours there is a merit based selection that is the selection is based on the the percentage on merit of your 12 graduation
the basic eligibility for bcom Hons is that you must have qualified 10 + 2 graduation from recognised board and your minimum aggregate should be 40- 60%
Best of four calculation method for bcom honours:
1. You must include one language subject which can be core, function, elective
2. You must include one relevant subject.for bcom Hons it is compulsory to include mathematics in your best of four.
3. Two subjects from list a
for list a check the university web portal where they have given the subjects that you can include in your best four in case you include a subject other than the ones given in list a then there will be deduction of 2.5% like if you include physical education of music in your best of 4 then there will be a deduction of 2.5 % from your overall best of four percentage.
Yes Maths is a compulsory subject to have in class 12th in order to take admission in Delhi University B.com(H) but however for B.COM(P) it's not a compulsion to have studied Maths in class 12th.
Hope this clarifies your doubt