Hiya,
Minimum requirement for CPL is Higher Secondary (10+2) not High School (10th) as advised by your friends.
In India, for 10+2, you would like to enroll at Open school, with just required subjects. Examination conducted twice a year.
www.nos.org
However, in US it is known as high school diploma grade 12 (as far as I know, please confirm it ). with online option with several schools. In this case you are required to take all the papers for both the subjects.
Please note, should you take it overseas (U.S.), you would need to get a evaluation done in India by Association of Indian Universities.
www.aiuweb.org
Good Luck!