I am not sure what you mean by "College mai normal less than 20 hrs ko work ra college mai CPT garna milcha?". You don't need to do CPT to work at your college, you can just work at as many jobs as you want on-campus as long as you stay within 20 hours during school(during break you can work +40). Getting CPT won't allow you to work more hours (the total still has to be 20 if you are not in your "vacation" period).

Legally, International students can work up to 20 hours weekly during school and +40 hours during break on-campus without any problems. However, if they want to work off-campus, they need to get authorization. If the work that they are planning on doing is related to their field of study and they have been going to school for at least eight months, they can do CPT. So in CPT you would be allowed to work the same number of hours (i.e. up to 20 during school and +40 during break) off-campus. If you do 1 year of full-time CPT you won't get OPT (meaning if you do four full-time internships during four summers you won't get any OPT but I highly doubt there are a lot of people who would be able to do that so for most people this is not an issue)


"Curricular practical training is defined to be alternative work/study, internship, cooperative education, or any other type of required internship or practicum that is offered by sponsoring employers through cooperative agreements with the school. Students who have received one year or more of full time curricular practical training are ineligible for post-completion academic training. "

Source: http://www.ice.gov/sevis/students/cpt.htm

It is always best to discuss these kinds of things with someone in your university (your adviser, international student office people etc) so that you get the most accurate information.