Economics

You are eligible for PO and clerical jobs in Public sector banks on completion of BA. You are advised to take bank coaching. In case you want to join private banks, it will advisable to do MBA preferably in Finance.

u r not eligible for btech
try for diploma or
do One yr.+2 in pcm from NIOS or
do mca after degree

CA, CS, MBA are good options where u can get huge salary

It is recommended that you do either MA Economics or MBA Finance to have a good career. You chose any based on your interests to excel.

For master's in eco u need Bachelor's in eco so it would be difficult to get admissions. Ignou take admissions with any Bachelor's degree so you must check with the university you wish to apply.

Computer Science is much better as compared to economic(hons). After completing your graduation in computer Science you may even land a job in multinational companies. Economic is also good but computer Science has more demand nowdays.

BA eco requires maths as one of the subjects in 12th so you cant because economics has lot of maths in it. If you are very keen then either take maths additional in 12th or appear for mathematics paper from NIOS. I am not sure if all universities will accept two score cards but you can try.