This happens in many Asian countries.
Say, students study math, chemistry, physics etc at school (primary/secondary or High school). But, a lot of them don't understand these subjects well enough.
And in order to "pass exams to get to higher grades" (I am not sure I am saying it correctly, these students need to pass the final chemistry/physics/etc exam at the end of each year to get to higher grade), they need to "attend some private tutorials / private lessons after official school".
In these private tutorials / private lessons, their tutors may not teach them the theory of these subjects because the students learned them in their official school. The tutors may focus on helping doing exercises of these subjects in stead.
Is it correct to say "Children in Asia often have private tutorials/lessons after official school to help them pass exams to get to higher grades"?