Hello Ayush,

There are several books, that are available such as those of NCERT, ISC, mathematics book authored by RD Sharma, etc. If you still want some higher level books, go for class 11th books. You may buy some previous year question papers or preparatory books of competitive exams such as those of NTSE, RMO, IMO and several other mathematics competitive exams and olympiads, as they have quite difficult and challenging questions.

Hope this Helps

Regards