Hello,

JNTU is a university so it has it's own materials and which you will get from the online webpage which is used by you students. You are in first year you might don't know but they upload every details in the student desk which is accessed by all the students and they are accessed by you only.

You can look for materials related to the subjects and you will get it in a broad manner and that might not be matching to the syllabus. To get saved from that huge material you can go for lecturenotes.com (//lecturenotes.com) where you will get all the materials with respect to branches and subjects.

Along with that you can study the prescribed books in your syllabus and you can additional information from the books from libraries. You will  other reference books there and you can use them to get specified or particular information.

Hope it helps!