my friend did apply at a college but the course only start in september now she want to know if her visa was only for six months and for waiting she want to know if she has overstayed will she be sending back to her country cause she dont have enough time

She should inform the home office, that the start of her couse date has changed, thay will issue her an extension on her student visa.

The home office says:-
If you enter the UK with a student visa or prospective student visa, or if you want to study on a course at degree level or higher, you can apply to the Immigration and Nationality Directorate, which is part of the Home Office. (Contact details are at end of this guidance.) The Immigration and Nationality Directorate will charge you a fee for any extension of your stay.

The maximum period of time that a student can stay in the UK on short courses one after the other, below degree level, is two years.

If you do not enter the UK with a student or prospective student visa, or you are not studying on a course at degree level course or higher, you will not be allowed to extend your stay.



This site has all the information you need and the possibility to ask them a question.