Agriculture Entrance Exam

You are eligible, but you have to show proper reasons for the gap in you student career. If you do not have any proper reason or a gap of more than 2 years, then you are not eligible.

Yes, there is negative marking in the entrance exam.

You will be asked everything from your 11-12th, so revise your basics and practice thoroughly.

Hello Arshad,
Some of the books which may be useful to you for preparation in to clear entrance for admission in agriculture in Pantnagar and other good agricultural universities in India are:
Arihant's B.Sc. Agriculture Entrance Exam 2019
New Vishal's B.Sc. Agriculture Entrance Exam.

Which exam are you applying for?

As per TNAU Information Brochure Undergraduate admission-2018, there is no any entrance exam for B.Sc (Hons) Agriculture. All the Undergraduate admission will be made on the basis of merit (class 12th) marks.
Selection process is done through online counseling. Here I would like to clear here that the online admission for the Academic Year 2019-20 will commence shortly through online mode. So, please go through the latest information brochure for more clarity.

Yes, this book will do to prepare agriculture entrance exam. The book is very helpful. But will suggest you to also add another book if you can, I. e. ICAR: AIEEA-UG (B.Sc. Agriculture) Entrance Exam Guide. This is specially published for the aspirants of AIEEA-UG which is conducted by ICAR, yo take admission under-graduate degree programmes in Agriculture field.