Hi

BCA subjects are not there in UPSC open but no worries you can choose any subject from the available list of optional subjects

List of optional subject is provided below:-

• -) Agriculture
• -) Animal Husbandry and Veterinary Science
• -) Anthropology
• -) Botany
• -) Chemistry
• -) Civil Engineering
• -) Commerce & Accountancy
• -) Economics
• -) Electrical Engineering
• -) Geography
• -) Geology
• -) History
• -) law
• -) Management
• -) Mathematics
• -) Mechanical Engineering
• -) Medical Science
• -) Philosophy
• -) Physics
• -) Political Science & International Relations
• -) Psychology
• -)Public Administration
• -) Sociology
• -)Statistics
• -) Zoology

List of literature optional subjects is provided below:

• -) English
• -) Assamese
• -) Bengali
• -) Gujarati
• -) Hindi
• -) Kannada
• -) Kashmiri
• -) Konkani
• -) Malayalam
• -) Manipuri
• -) Marathi
• -) Nepali
• -) Odia
• -) Punjabi
• -) Sanskrit
• -) Sindhi
• -) Tamil
• -) Telugu
• -) Urdu
• -) Bodo
• -) Dogri
• -) Maithili
• -) Santhali

You can check the same at

https://competition.careers360.com/articles/upsc-ias-syllabus

You need to choose one subject for optional for your UPSC main examination and  there will be two papers for your optional subject.

• -) both your optional papers carry 250 marks each
• -) your optional papers will be subjective
• -) your optional subject question paper will be set in both English and Hindi except for the literature subject

Now,

Which optional subject you should choose completely depends upon your interest. But yes, if you choose subjects like geography etc then it will help you in your gs as well.

Some of the best optional subjects are :-

• Public Administration – Highly relevant,  it has compact syllabus, it has a lot of overlaps with your polity & governance part in your GS II.

• Sociology – it's study of society, lots of material are useful  in GS I, Essay, in Ethics paper as well.

• History – useful for prelims and your GS I.

• Geography -relevant for both prelims and GS I

• Political Science – relevant for both prelims and GS II

Some other good optional subjects are Economics, Philosophy etc.

So, take your time and decide.

Thank you