The minimum eligibility for pursuing CA course is 10+2 examination from a recognized board.
After 10+2, one needs to register for ICAI's Foundation (4-month study period), pursue BCom (simultaneously), and enroll for Intermediate (8-month study period). Next, they should pursue three-year Articleship and clear the Final exam.
The duration after 10+2 is about 4.5 years. However, after graduation, one can directly enroll for Intermediate.