Plant Physiology carries 6% weightage in Neet. Plant physiology covers around 5 chapters - Transport in Plant, Mineral Nutrition, Photosynthesis in Higher plants, Respiration in Plants, Plant growth and development. Photosynthesis and respiration- One of the most important topics for Neet. You must cover these topics with sincerely. Understand and memorize the plant hormones and their functions, and effects, Essential Mineral Elements, transport in plants, physiology of seed dormancyetc. You can make charts for different cycles of plant physiology for better understanding. Preparing from charts and tables helps in memorizing. To score good in Neet, you must go through NCERT textbooks thoroughly as most of the questions are directly asked from it ans NCERTs cover the entire syllabus of Neet. After that you can opt for standard reference books like Truman' elementary biology Vol 1. Go through the link for study materials and most asked concepts
http://learn.careers360.com/biology/plant-physiology-chapter/