hi,

every year ICAR conducts AIEEA exams for admission in different agriculture related ug courses. Candidates need to choose subject as per their Eligilbility Conditions for different UG Programs. now you must have the subjects which is prescribed in official brochure to become eligible for the exam, for example

bsc in agriculture course candidates must have studied  PCB/PCMB/ PCM/Inter-Agriculture in 12th course, aspirants takes subject papers in exam center is either of PCB/PCM/PCA/ABC. now I would suggest you to take the subjects which you have studied in 12th , because in a short time it is difficult to have good grip in any subject.

hope you may understand.