Im buying a graphics card soon, i have a 460W PSU can the R9 270X run on it ? or do i need a 500w one? and one more thing can R9 270 run on 460W?

If that is a quality PSU, 460W is more than enough for a 270x.

What is the make and model of the PSU?

I have coolermaster RS460

I dunno about the RS460. That has less 12v amperage than the FSP Hexa+ 400W.

While 460W is more than enough to power a 270x, the PSU you have only can deliver 312W on the 12V rail which is cutting it too close in my opinion. Most highend PSUs rate the capacity of the PSU near or same as the amount of power the  12V alone can provide.

For example, a Seasonic G series 450W can deliver 444W on the 12V rail alone. If you had a similar PSU, then you are good to go.

Can you list the rest of your PC specs? If you have a Core i3, 4GB RAM, just one HDD, then you might be able to sneak it in. But forget about overclocking.

i3, 4gb ram, 1 tb HDD and 2 500 gb HDDs

its this one btw
http://www.coolermaster.com/product/Detail_print/powersupply/office-home-extreme/extreme-power-plus-460w-120mm-fan.html

It might be enough if you don't overclock it.

ok ty