Finding previous year's question papers for NDA can be a helpful way to prepare for the exam. These question papers can provide insight into the exam pattern, types of questions asked, and the level of difficulty. However, it might be challenging to find question papers that include questions from all three branches (Army, Navy, and Air Force) as the NDA exam is conducted separately for each branch. Nevertheless, there are a few ways to access previous year's question papers that cover all three branches:

1. Official Websites:
- The official websites of the Indian Army, Indian Navy, and Indian Air Force might have previous year's question papers available for download.
- Check the official websites of the respective branches and look for sections related to recruitment or exams. Often, these websites have a dedicated section for previous year's question papers.

2. Educational Platforms:
- EduRev is a popular educational platform that provides access to a wide range of study materials, including previous year's question papers.
- Search for NDA question papers on EduRev, and you may find question papers that cover all three branches.
- EduRev has a vast collection of study materials and is a reliable source for exam preparation.

3. Coaching Institutes:
- Many coaching institutes offer NDA exam preparation courses and materials.
- These institutes may have previous year's question papers that cover all three branches.
- Contact coaching institutes that specialize in NDA exam preparation and inquire about the availability of such question papers.

4. Online Forums and Communities:
- Online forums and communities dedicated to defense exams like NDA can be a valuable resource.
- Participate in these forums and ask fellow aspirants if they have question papers that cover all three branches.
- Members of these communities often share study materials, including previous year's question papers.

Remember to verify the authenticity and relevance of the question papers before using them for preparation. It is advisable to focus on recent question papers as they are more likely to reflect the current exam pattern and syllabus. Good luck with your NDA exam preparation!