Let me start by saying that there is no definitive “best” optional subject for everyone. Each individual has their own strengths, interests, and abilities. For some of you, a technical subject is better, others can write well in Humanities-based subjects. But the fact of the matter remains that It’s important to choose a subject that you are genuinely passionate about and confident in your ability to master.

Despite that, here are some factors which you may take into account while choosing an optional subject:

1. Previous Knowledge or Background: Consider your educational background and previous knowledge in a particular subject. If you have a degree or prior exposure to a subject, it can give you an advantage in understanding and preparing for that optional subject.
2. Scoring Potential: Look into the scoring potential of different optional subjects. Analyze the previous years’ question papers, trends, and marks distribution for each subject. Some subjects may have a reputation for scoring well or have a higher success rate among candidates. However, keep in mind that scoring is subjective and depends on individual performance.
3. Interest and Aptitude: Start by assessing your interests, strengths, and aptitude in various subjects. Choose a subject that you are genuinely interested in and have a good understanding of. Remember, you will be studying and preparing for this subject extensively, so it should be something you enjoy and have a natural inclination towards.
4. Time and Effort: Consider the time and effort required to prepare for the optional subject. Evaluate the complexity and depth of the syllabus, availability of study time, and your ability to comprehend and retain the subject matter.
5. Syllabus Analysis: Review the syllabus of the optional subjects provided by the UPSC thoroughly. Analyze the topics and sub-topics covered in each subject. Consider the overlap of the optional subject with the General Studies papers and the overall syllabus. Look for subjects that align with your strengths and have a manageable syllabus.
6. Availability of Study Material: Check the availability of study material, books, and resources for the shortlisted optional subjects. It is essential to have access to relevant and quality study material to aid your preparation. Ensure that the subject you choose has ample resources and references available.
7. Coaching and Guidance: Evaluate the availability of coaching and guidance for the shortlisted optional subjects. Some subjects may have more coaching institutes and experienced faculty members to provide guidance and support. If you feel you need coaching for a particular subject, check if it is readily available.
8. Consultation and Advice: Seek guidance from experienced mentors, teachers, or successful candidates who have already appeared for the UPSC exam. Their insights and suggestions can help you make an informed decision.

Optional Subject plays an important role in deciding whether your name appears in the final list or not. Therefore, it is important to do your due diligence on the same.