Hi, Nandini

To study economics, one needs to have a thorough knowledge of the subject maths. Taking up economics in your 12th standard helps in making it easier to study the subject later. It is difficult to study economics if your concepts of maths and economics are not clear just like it gets difficult to study physics at times due to the lack of knowledge of the subject, maths. In my recommendation, you shouldn't opt for the subject if you don't have the required knowledge. 

Hope this helps you! 

Hii you cannot opt for economics as a optional subject in mounM Carmel college Bangalore because you were not having economics in eleventh,and twelth because for having economics in graduation base should be there of the subject,hop h your doubts are clear now,so good luck