Hello,

You can get most of the books if the author is a foreigner. for Indian author, it is hard to get. you can get notes from lecture notes official webpage.

You will get mostly 70-80% of books online. for rest of the book either you have to buy else get from library if it is not available online. If you can manage by notes for them then that is okay too.

Main objective is to learn the concept and know what is actually happening. and use them when it is required to solve a problem. Meaning of engineering is to solve a problem in very easier and simple way.

Hope it helps!