should jean pants should be allowed in colleges ?

Actually here in America most college studends wear jeans most of the time and sometimes even sweatpants. Unless you go to certain private schools the dress is almost certainly very casual for college students. Actually there have been studies that show that people tend to be more productive when they are dressed comfortably. Even many work places in the US have gone to business casual dress all the time or at least have casual Fridays where everyone can wear jeans, that is usually upheld unless an important client is coming in and then they may require that you dress up.