How can I simulate Real camera "white balance" parameter in KELVINs There is some presets in Color Management tab under "look" setting or via curves, but no custom setting that can bet set up with kelvins.
'Looks' is meant to simulate the way different films respond to light, not quite the same as white balance.

To render lights at different colour temperature, you can use the 'Blackbody' material node to convert a Kelvins Temperature to an RGB colour: