There are several resources available for studying ethics in UPSC Philosophy. These resources can help candidates understand the concepts, theories, and principles of ethics, which are essential for the examination. Here are some of the best resources for studying ethics in UPSC Philosophy:

1. NCERT Books:
- NCERT books on Philosophy, particularly Class XI and XII, provide a solid foundation for understanding the basic concepts of ethics.
- Candidates should thoroughly study the chapters on ethics and moral philosophy in these books.

2. UPSC Syllabus:
- The UPSC syllabus provides a comprehensive outline of the topics and subtopics that candidates need to cover for the examination.
- Candidates should carefully read and understand the ethics portion of the syllabus to know what to focus on during their preparation.

3. Reference Books:
- Several reference books are available in the market that cover ethics in detail.
- Some recommended books include "Ethics, Integrity, and Aptitude" by G. Subba Rao and P.N. Roy Chowdhury, "Ethics, Integrity, and Aptitude" by M. Karthikeyan, and "Ethics, Integrity, and Aptitude" by Lexicon Publications.
- These books provide in-depth explanations of the various ethical theories and principles.

4. Previous Years' Question Papers:
- Analyzing and solving previous years' question papers is an effective way to understand the type of questions asked in the examination.
- Candidates should practice solving these papers to get a better idea of the exam pattern and the level of difficulty.

5. Online Platforms:
- Online platforms like EduRev provide a wide range of study material, including notes, videos, quizzes, and mock tests, specifically tailored for UPSC Philosophy.
- Candidates can access these resources to enhance their understanding of ethics and practice answering questions in a timed manner.

6. Coaching Institutes:
- Joining a reputable coaching institute can be beneficial for candidates preparing for UPSC Philosophy.
- These institutes provide guidance, study material, and mock tests to help candidates prepare effectively for the examination.

In conclusion, studying ethics for the UPSC Philosophy examination requires a comprehensive approach. Candidates should utilize a combination of NCERT books, reference books, previous years' question papers, online platforms like EduRev, and coaching institutes to enhance their understanding of the subject and improve their chances of success in the examination.