Is it likely that I'll have courses with my high school mates when we go to the same college?

That depends on how big the college is and whether you'll be taking the same courses.  Even then, many courses have "sections", which means the classes are given at different times of the day.   You might have Bio 101 at 9:00 and a buddy has it at 1:00, for example.

It really depends on factors such as the size of your college and the majors you all choose.  At large schools there are many sections of the required gen ed courses that everyone takes, so there is a good chance you'll end up spread out.  In smaller schools there are fewer sections, so there is a better chance that you'll end up having some together.  

In what country? 

Many students from my high school went to Illinois State University.  I rarely saw any of them. Although all freshman take similar classes. That doesn’t mean you will have any classes together. 

Schedules can vary greatly. You should have a lot of free time at the same time. 

The larger the university the more likely you won’t have classes together. 

Not if it's a large university. There will be many, many sections of the courses for freshman. There may be large lecture sections for some freshman courses, but those are in auditoriums, you won't be sitting together, and there won't be much interaction in those classes. In smaller classes, like freshman composition, there are so many sections that you're unlikely to be in class with more than one person you know. Anyway- people change in college. Those awful high school dynamics don't apply any more. 

i think its possible

It depends on 1. the size of the college and 2. your majors. I went to the same university as three other people in my high school; I ran in to one of them, once, in all four years.