There are some institutes which don't share there entrance examinations papers. As a result the information doesn't get outsourced. Now if a person somehow gets a physical copy then he/she uploads it in the website. So all websites didn't have the question papers.

Although career360 has quite a good amount of papers be it past year or sample year. You can ask about your exam, if the papers are available then the link will be provided to you.

I hope this answer helps. All the very best for your future endeavors!