Question

why when we feel cold water in bottle then a droplets of water come out automatically

Answer 1

When water vapor in the air comes into contact with something cool, such as the outside of a cold glass of lemonade, its molecules slow down and get closer together. When that happens, the gaseous water vapor turns back into liquid water droplets. That's condensation!

Answer 2

when cold water or any other cold thing comes in contact with the air then due to difference in temperatures the water vapours surrounding the cold water container gets condenses and tada..you get droplets of water.