Study materials for the organizational theory and behavior topic in UPSC Management Optional subject can be found on various online platforms and websites. Here are some suggestions:

1. EduRev:
- EduRev is a comprehensive learning platform that offers a wide range of study materials for UPSC Management Optional subject, including organizational theory and behavior.
- It provides detailed notes, video lectures, practice questions, and previous year's question papers for thorough preparation.
- The platform also allows users to interact with experts and fellow aspirants, enabling collaborative learning and doubt clarification.

2. UPSC Official Website:
- The official website of UPSC (Union Public Service Commission) provides access to various resources for UPSC exam preparation, including the optional subjects.
- It offers previous year's question papers, syllabus, and recommended reference books for each subject.
- Aspirants can also find notifications, exam patterns, and other relevant information on the website.

3. Online Forums and Discussion Platforms:
- Online forums like Quora, Reddit, and various UPSC preparation websites have active communities where aspirants share study materials, strategies, and insights.
- These platforms often have dedicated sections or threads for the optional subjects, where study materials for organizational theory and behavior can be found.
- Engaging in discussions and seeking guidance from experienced aspirants can be beneficial in understanding the subject better.

4. YouTube:
- YouTube is a popular platform for educational content, and there are several channels that provide lectures and tutorials on organizational theory and behavior.
- Channels like Unacademy, Study IQ, and Mrunal offer comprehensive video lectures specifically tailored for UPSC Management Optional subjects.
- These videos provide conceptual clarity and can be a valuable resource for visual learners.

5. Library Websites:
- Many university libraries have digital resources and online databases that can be accessed by students.
- Check your local library's website or university library websites to see if they have any e-books, journals, or research papers related to organizational theory and behavior.
- These resources can provide in-depth knowledge and help in understanding the subject from an academic perspective.

By utilizing these online platforms and websites, aspirants can access a wide range of study materials, lectures, and practice questions to effectively prepare for the organizational theory and behavior topic in UPSC Management Optional subject. Remember to cross-reference the information and prioritize quality resources for better learning outcomes.