I have a 500W psu without 6 pin.I bought a new gpu and i need it. Can i have just 1 molex to 6 pin or I need 2 molex to 6 pin
What psu? 500w means nothing and we don't know the quality. What gpu? Generally if the psu does not have the connectors that means it is NOT up to the task to run said device. Even a psu that can run it by using adapters is heavily adviced against as you are putting a big strain on a rail that is not neccesarly intended to give that much power.
Get an EVGA PSU. They're good for a decent price. Get more watts than you need. 80+ Gold. If you need 500W get 600W. I usually do 100W more than needed for headroom. Overworking a PSU is a bad idea.