is all iBook textbook available in India

Dear friends,

I am feeling a lot relieved to contact you.I use an iPad because the iBooks textbooks it offers is great and i think it may improve my learning exprience in my own field(also to name the educational apps). But i am not sure about the availability of this textbooks worldwide. I am a citizen of India . I visited the apple( India ) official website i.e- www.apple.com/in/ and tried to satisfy my query but there I did not found much information about the iBooks textbooks and use of iPad in educational field. ** in apple( USA ) website( www.apple.com/ - United States ) I found detailed information about those . I searched here and there for answer to my question but in vain . Therefore I request you to help me to get the query solved........