colaour cast

Do i adjust white balance in camera to reduce or eliminate red colour cast from
down lights and green from fluros or do i do this in PP ?

I'm not an expert, but I think that the more stuff you can get right in the camera, the better you'll be. I vote for in-camera white balance.

Post processing is great (in fact, it's my life), but nothing beats a good photo straight out of the camera!

May i then ask approximate recomended adjustments of white balance if you would be so kind

Sorry, not a photographer. Anyone else?

Photograph a neutral grey card or a sheet of white paper, without EC, under the same lighting as your subject. In camera's menu go to Custom WB. You will be asked if you want to use that photo for creating CWB. Answer yes. Go to WB sub-menu, select Custom.

or just use flash, its white light so no color cast. what they flash dont reach will turn what ever color the light is tho...