can my psu support vapor-x r9 290x?

No. That PSU is not good quality and I would replace it for sure before using a 290x. Antec, XFX, Seasonic, EVGA (G2,B2,GS) are what you want.

You know Coolermaster know your PSU isn;t good because they only gave it 2 PCI connectors. Most quality 650w units have 4 and only 500w units have 2.
 
I mean it is not a good quality PSU and I would not use it period. The 970 uses much less power than the 290x so there is a chance it will work better, but remember that because it is low quality it still has the possibility of damaging the components of the PC by providing unstable power, alot of ripple, and poor regulation. Using a 970 instead will probably lower the chance that the PSU fails completely and fries the entire PC, but that is still a possibility no matter what.

The PSU is the single most important part of the PC. NEVER risk the computer to a junk unit. Buy a proper one.

To answer the question, a 970 would be WAY safer than a 290x(which I do not recommend at all for this PSU) but I would still recommend buying a proper unit over using it at all.