Hello,

you must first mention that from which subject group you are going to write the exam.

However the general agriculture part is common for all and the book of Nem Raj sunda and Arun katyayan are the best for it. For objectives of general Agri the book by S.R. Kantwa is the best. These 3 are more than enough to serve the purpose. Other than these if you wish more than any agronomy book of field crops and basics from a soil science book like that of by D.K. Das can be studied as agronomy and soil science are important topics.

hope this helps you !

all the best !