[Prathamesh]

i read that Hypochlorus acid (HOCL) OR Hypochlorite ions (OCL-) are found in water, and they are called 'free chlorine'

why is one HOCL and  the other OCL- when it's an ion?

[Borek]

Acids dissociate in water (they wouldn't be acids otherwise), so they are always present in some equilibrium amounts with the dissociated form.

To make things even more complicated in this particular case free chlorine (Cl₂) is in the equilibrium with the hypochlorous acid. Calling it 'free chlorine' is kind of a misnomer, although in some respects it behaves as if it was the free chlorine alone.