To become an Actuary, basically you need to have very strong mathematical skills, sound communication skills and a savvy for computing. You do not need to have studied Mathematics or Actuarial Science in the higher institution. Many persons have been able to enter the actuarial profession to the top levels, from first degrees of Engineering, Physics, Statistics and so on. Your Senior Secondary Certificate Exams mathematical exposure and passion will be critical. There have also been reports of persons moving from the legal profession into Actuarial Science (Obviously, these persons must have had a remarkable mathematical background and bias).
Your interest and passion for mathematics and problem solving and your determination and hardwork, will be critical to succeeding in an actuarial career. It could be helpful to speak to an Actuary for his/her opinion and advice, before you embark on an actuarial career.