Hello dear
CA is conducted by ICAI. There are three levels in which you have to pass all exams.
You can join only by registering through ICAI website by creating your portal. After 12th class you have to start from foundation level and after college you can directly enter to the course from intermediate level. There's no particular college for for that you can graduate from any institution.

• First level that is CA foundation consist of 4 papers
• Second level contains 8 papers divided into 2 groups of 4 papers
• After intermediate level passing in either of the group or both of them you need to do Articlship of 3 years.
• Last level is the final exam which again consist of 8 papers divided into 2 groups.

After completing this course of minimum 5 years you'll become CA.
thank you