See UPSC is an commission, it is not an exam. UPSC conducts various exams CDS, NDA, Civil Services etc. And i think you are talking about Civil services exam, for that or any exam conducted by UPSC, they ask questions which sometimes do come from those. Because these books of NCERT will make your base strong. Basically it is asked to read from 6th till 12th. But it is upto you. But from 10th till 12th you should read. They will be helpful for any upsc exam you are preparing for.