I know black is the absence of light but still if we can create white light black should be possible right? A torch with black light that if we glare it in the day a certain place becomes dark...?
Black light is just a common name for ultraviolet light . It is a misnomer that has worked itself into common usage. There could be no REAL black light .
there already is a black light.
If I'm understanding you correctly, no. As you said, black is the absence of light, thus you could not produce a light the emitted black light. However there are black lights that are actually emit violet and UV rays and you can certainly have a pretty dark violet color.
Black light does exist. It is the light that makes everything glow when put under it. Basically it is a very High UV Light. Contrary to your belief, you can't create something in which emits a Opposite Light or Black light to make Light look dark. This is because every thing we see is part of the light spectrum. So the only way to do this would be by Blocking light, for instance closing the window.
