Hello Jayant,

we can't consider any book as the best book for study any thing.As you are doing B.Tech there are many book available for different subjects written by different writers.You can choose any of the which can be easily available to you.Also you can't get all your syllabus in a single book,you have to study for that subject from different books.Also you can prefer the you tube to study anything which you want,related to any subject.