ICAR AIEEA

If you are a Stream A student, then you can attempt questions of Physics, Chemistry and Biology sections as there would be 60 questions each (180 questions total). There is no need to attempt questions of Agriculture and Mathematics section, as out of five sections only three sections are to be attempted. While preparing for the exam, give equal emphasis to Physics, chemistry, and Biology as there are 60 questions each. You can cover your 10+2 level PCB books for this exam, if you have been studying for medical entrance examinations like NEET then that preparation should be sufficient. No need to study Agriculture related questions or General knowledge. Always follow the syllabus given in ICAR official website - Syllabus
You can check the scheme of examination here - Scheme of Examination
Note: Those who have Agriculture as a subject in their 10+2 can attempt questions of Agriculture section and two more sections based on their 10+2 subjects.

Yes, it is mandatory to complete and send the ICAR AIEEA form to the address mentioned below:
After filling the application form online, aspirants need to take a printout of the confirmation page as well as Bank Challan (3 copies). Aspirants are informed: Application should be sent through Speed/Registered post only and any application sent through any other mode like private courier service, fax, e-mail, etc. Shall not be entertained. Duly filled application forms need to reach the below mentioned address within stipulated time:
Office of Controller of Examinations (Agril. Education), ICAR, Room No. 216, Krishi Anusandhan Bhavan-II, Pusa, New Delhi 110 012.