Yes, for the sample papers or practice papers you can opt for books by Arihant or R Gupta's as they have books especially designed for this entrance. If you want past papers, you will get them there. If you want the official papers made available by JNU itself, you can find them on their website. The link is given below:

https://admissions.jnu.ac.in/searchquestionpaper.aspx

Hope this helps.