When I was in 6th standard I was used to buying book from Jain Book Depot, this book depot is very OLD and you can find almost all type of books and second hand book is also. Me and my brother used buying books from here. And I have recommended this book depot to my younger friends who preparing for govt. jobs exams. and you can find here all type of book for competitive exams like SSC CGL, SSC 10+2, IBPS, LIC AAO, LIC ADO, CTET, .NET and many more. so please visit this book depot to buy useful books for competitive exams. Thanks. :-)