Hii Kritika,

Yes, you can pursue M.Com after BBA . 

As far as DU is concerned, you can appear in the entrance test and if you qualify then you can get admission there. 

M.Com degree holder can work as:

• Assistant Accountant.
• Accountant.
• Senior Account Executive.
• Cashier.
• Personal Finance Consultant.
• Business Consultant.
• Teachers/Lecturer.
• Executive Assistant etc. 

Hope the answer is helpful.

Good luck!