Commerce

If you are good at acting, then concentrate on the same.

Hello Amardeep,
Your cousin seemed to have obtained reasonable marks in 12th. Admission process in DU is online merit based or entrance exam based depending on course sought.

You can do English honors or any other course even B.Sc through distance learning mode. Along with it, you can learn any foreign language. Japanese can be preferred or you can prepare for bank PO, along with your graduation or give it after graduation.

No, you cannot do architecture, if you are from commerce stream. From 2018 on-wards, only science (PCM or PCMB) students who have scored at least 50% marks in class 12th with mathematics, as compulsory subject will be considered eligible to appear in architecture entrance exams.
Before 2018, commerce with maths students who have secured at least 50% marks in class 12th are eligible to appear in architecture entrance exams like NATA, JEE Mains paper 2 etc.