600 dollar build
With a gtx 760 and a fx 6300. If possible, with the os
You will have 130 dollars left to spend on the PSU, motherboard, RAM, chassis and hard drive. This will be very difficult to do without skimping on the components. I don't recommend.
This is assuming you're buying a $100 copy of Windows. Or are you using Linux?
EDIT: Please check out this other thread. The guys over there have some solutions for a little over $600. http://www.tomshardware.com/answers/id-1869920/600-dollar-budget-build.html