Question

how can i score 90 above percentage in 10 th?

Answer 1

Don’t count hours, study till you understand a topic completely
. As soon as you understand something, write it down in your own language to make your own notes.
Important thing is the planning. To make sure that you do not lose your track in between, you must have a solid plan of study. Make a plan in the very beginning and follow it for the complete year. 
Start off from the topics that you don’t have much confidence on. These topics are the ones, which are difficult for you to understand, to grasp and to remember. 
Study those topics first, keep two books with you (one rough and the other for revising it during exam).
Make your own notes for the difficult topics first.The next thing is the study pattern. If you really want to achieve that 99% target, you must love your books. Yes, you must be completely in love with them
. Do not take study as a burden, but try to like it. Your study pattern plays a big role
. Try to make your study interesting
.Make a schedule (time table), which would eventually help you in tracking your completion everyday
.

Answer 2

at first just focus on ncert books for all subjects