Check if your power supply has a plug with 6 pin socket connector or if the card comes with a 6 pin socket molex adapter if your power supply doesn't come with a 6 pin.
Look up the specifications of your power supply. Even if you don't have a 6-pin pci-express connector, you can get an adapter that connects to two spare 4-pin molex connectors. However, you should also check how many amps the psu provides on the +12V rail.
Most GPUs that require extra power connectors include an adapter in the box for power supplies which don't have the 6 pin connector built in. It's an adapter with two four-pin MOLEX connectors leading to one six-pin GPU connector.
sorry for the confusion, i was just trying to give him/her an idea that good psu's (550w for example) has 2 6-pin usually. more for higher capacity psu's
anyway, i would advice that you start saving for a decent psu. having no 6-pin is not a good sign