Q.eggplant
whats going on

This could be due to watering issues, environmental, pests, disease or nutrient problems.
Difficult to say from this image, but these links may help you pinpoint the issue when you compare to your growing conditions and soil.
https://www.gardeningknowhow.com/edible/vegetables/eggplant/growing-eggplant.htm
https://www.gardeningknowhow.com/edible/vegetables/eggplant/eggplants-turning-yellow.htm
https://www.gardeningknowhow.com/edible/vegetables/eggplant/eggplant-problems-eggplant-pests-and-diseases.htm
https://www.gardeningknowhow.com/plant-problems/environmental/leaf-chlorosis-and-iron.htm