officer training academy CDSOTA is conducted in pen and paper mood. syllabus is consist of only english and general awareness. questions are in multiple choice type. totsl 240 questions need to answer, also there is negative marking. age shold be between 19-25. you can follow below mention books for your preparation.
Combined CDS (OTA) Book , DDE – Defence Direct Education
Pathfinder CDS by Arihant Experts
Lets Crack CDS Exam by SSBCrack