You nust prepare via multiple quizzes and tests and previous year questions sets on below website. 

http://www.nism.ac.in/certification/index.php/136-others/312-download-tutorial

You should revise basic cincepts from books like following available for free download below:

https://www.prepcafe.in/nism-study-material&ved=2ahUKEwig_7Xw3oreAhUHcCsKHYx-CjwQFjACegQIBBAB&usg=AOvVaw2DnW6vSSAIdMC9Sub0VUKy