Hi Nikhil, 

I assume you are asking about the percentage required in class 10 to opt for PCB in high school. Well, that differs from school to school. Most school expect the students to get a score of 8 CGPA and above, while some accept students with less than 6 CGPA too. But it is safe to say that your target should be more than 8 CGPA. 

Getting a lesser CGPA in 10th doesn't mean you cannot do it in 12th. More effort can definitely get you a seat in a better college. 

All The Best.