My evergreen recommendations for science books in Class XI and XII are NCERT books which you can download from their site for free, or buy from a nearby bookstore. Not everyone believes in this recommendation though – for some these books are too brief and cryptic.
Here are some of the books that I used when I was a student almost 30 years ago, and I find that they are still the favorites!
A remarkable book, and if you have to choose only one book to study from, this is the one. When I studied (1990-91), it was a thin book, now it weighs more than 5Kgs!
A great collection of really tough physics questions. You can also find solutions book for this, which can be a good companion book. When I was studying, this book was a craze, and people who used to regularly quote from this book a question they had solved, were considered genius!
Recommendations from a friend