Why would he get chicken feed? I have no idea what the situation with rabbits is in Pakistan, so i don't want to make any assumptions, but it seems like breeders over there are lumping rabbits in with chickens? As far as i know, rabbits and chickens couldn't have more different diets and nutritional needs (although both are herbivorous) so why are rabbits given chicken food, is still a mystery to me.
What cncerns your rabbit though. Do keep watermelon, apple, carrots, beetroots and whatever whatnot sweets (especially anything that contains milk, meat: those should never be fed to rabbits, and even grains and corn aren't that good) that isn't hay or fresh, clean grass, off of his diet for a good long time. Then, maybe after a week, two or even more, depending on if the issue is in your rabbit's food, his poops should be constantly stable again. His activity should return as well, but do be aware they're more couch-potato-esque during high noon. Only after that can you reintroduce all that sweet stuff, but never much, never too suddenly, and never at once. The most common measurements i remeber are 1-2 tablespoons (say 5-15 grams depending on what it is) per 5 lbs of body weight? So even with a big rabbit that is around 10-12 lbs (or 4-5kg) they should ideally get no more than a tablespoon of treats per day.
In your scenario though, until you find something of better quality than the chicken feed (maybe you have something from that green list, or avaliable to order online without outrageous shipping:
Rabbit Food Comparision - Brand, Type, Nutritional Analysis ), try reducing its amounts slightly, and leave out any and all sweets for the time being. Of course he would be picky about his hay when he would normally get all those treats.
Hoping all the best with a diet change for the better.