My boss is trying to find out who has the TV/Film rights to a certain short story. Does anyone know how I would go about getting this information? Much appreciated.

I assume you are talking about a Ray Bradbury story. If so, you should contact his literary agent, Don Congdon, whose address and phone number can be found by clicking on the link below:
http://www.writersservices.co.uk/WrHandbook/us_don_congdon.htm