CBSE 12th

For admission into MCA, the candidate must be graduate with Mathematics or Statistics as one of the primary subjects at the degree level and Mathematics at the +2 level. In addition, the candidate must also qualify the DEET.
Meanwhile, any graduate who studied mathematics or statistics as one of the primary subjects at degree level, and mathematics at +2 level, can apply for admission into the M.Sc program. They wont require appearing in DEET or any other entrance test.
Only those who can furnish all necessary documents, including either Provisional or Degree
Certificate, as well as the marksheets of all the semesters at the time of the admission, will be eligible to apply. Those who obtain their undergraduate degree via the Off Campus route are not eligible.
Also, those who have already enrolled themselves for another program or are still undergoing the program, will be rejected.

Dear Zaid,
Don't be confused, there is sufficient time in your hands. So, first come down or meditate a few minutes. First, you need to make a time table to study at home. All subjects must be included in the schedule. The subject in which you are comparatively weak must be included everyday time table. When you study, let your mind concentrate on studies, don't let your mind get diverted. In the beginning, it will be difficult, but slowly you will be able to control your mind. You can continue your studies until and unless you feel bored. When you feel bored take a break and have a bite of a chocolate or a refreshing drink. If possible, minimise the use of electronic gazette such as mobile, tabs, computer, etc., but you can listen to the soft music to refresh your mind. Judiciously use your time and systematically start your study, You can notice the change after one month, not in one day. Now, let's discuss your school learning. When your teachers make you learn something, you must make it clear so that while revising the same at home, you must not have any doubt. Still, if you have doubts, you must clear it in the class or meet your teacher individually the very next day. You must not wait for next class because you may forget your doubts for the next class if the subject's turn is scheduled to come after two or three days. You can take help from your friends also. Peer group learning helps students a lot. So, think positive and go ahead. Success is at your door, you only need to open it. Hard work never goes in vain. Best of luck for your exam and wish you a successful life ahead.

First you should decide what you want to do: BA or appear for the UPSC exams. If you are aiming to do BA economics you should try and score high marks in your 10+2 level examinations so that you are eligible to gain admission in BA economics in a college of your choice.
If you are interested in the civil services, you should devote yourself to studying for the UPSC exams,as this is no mean task. You will have to study at least 8-10 hours a day depending on your capacity to grasp different topics.
So basically, you should first sit down and decide which course or exam you want to give. You could also take the help of a career counselor to help you decide on a favorable course.