Hello Shivalin

The best book for Mechanic in B.Sc is Mechanics by D.S. Mathur (S. Chand Publishing) it's  one of the oldest books that is still being used by many students across the country.DS Mathur is considered to be the topmost physics author of the country and  majority of the colleges and universities follow this book as a reference and also as a textbook.

hope this helps you