pigeon is alive but not eating by himself for last 3 days

When birds don't eat it means they can not process food normally - they are too sick and weak, too exhausted, their digestive tract is inflamed or damaged, full of fungus, parasites, bacteria etc.
In such cases just feeding can do more harm than good. For example a very sick bird that is going in to sepsis would need to be warmed up, provided with Iv fluids first before soft food is given untill the medication works enough for the bird to digest solids. In the other case if bird has internal injuries it should be warmed only if the temperature drops too low and might not be able to eat solids for a very long time. This is why you really need an opinion of a vet. Any opinion provided her has a chance to be wrong and kill the bird.

mohit78 said:

i found injured pigeon she is not eating anything .i see inside her beak dont find anything abnormal(i am not pigeon expert)
but pigeon one eyes is not in good condition. i am attaching her eye and poop pic View attachment 105401 View attachment 105402 pi

Click to expand...

She might have a liver or intestine disease but you really need to bring this pigeon to a vet for some tests. Only when you know what causes the problem then can you treat it accordingly. milder problems could be treated at home but what she has is very serious and only a professional could appropriately help.