For physics, do not ignoreConcepts of Physics by Dr. H C Verma. Two questions in the first part of the 2014 question paper were modified questions from this book. Also,Principles of Physics by Resnick and Hallidayhelps. A lot.

For Chemistry, do not refer any book other than theNCERT books. Chemistry is the simplest section in KVPY. However, do referA new pattern textbook of Inorganic Chemistry for JEE by Dr. O P Tandonfor the chapterCoordination Compounds.Especially forCrystal Field Splitting Energy.

For Biology, the good part is that many large, time-consuming lessons can be skipped. Analyze the previous years' question papers to get an idea. Then study theNCERT books, NCERT exemplary problems.Now you're 50% ready. After you've finished the syllabus this way, readBiological Science by Taylor, Green, and Stout,Cambridge University Presspublication.

I followed these steps and managed to get a relatively high score ( > 75 ) in the aptitude test.