Follow the books that you have studied in your undergraduation. You can go with Arihant Publication Books. Other books you may follow- Logic by Priyedarshi Jetti, Monica Prabhakar. Focus more on topics like History of Philosophy, Epistemology, Logic, Social and Political philosophy etc. We have Sample papers of JNU MA Philosophy entrance exam which you can solve https://university.careers360.com/download/sample-papers/jnu-entrance-exam-ma-in-philosophy-sample-paper-2014