dudeman509 :
Tanvir Sandhu :
no i have a ddr4 ram. not ddr 3
Then go with a Skylake build.
Yep.
It would have been best to say you had 12GB of DDR4 at the start as most people would assume it's DDR3 froma previous build and you're just upgrading the motherboard and CPU.
(again, there are some Skylake motherboards that use DDR3 but those are to be avoided due to CPU damage.. and the fact your DDR4 memory won't work)
So yeah, the i5-6600K plus compatible motherboard is what you want. Maybe one of the Asus Z170 boards like the Z170-A.
Other:
How is it you have exactly 12GB of DDR4 anyway?
If you have 3x4GB then make sure you can use it that way with no bandwidth loss. I don't know if DDR4 supports triple-channel (otherwise it operates in single channel mode). I don't see any triple channel memory kits so I'd be surprised if it did.
If not, you'll want to use 2x4GB or buy a different kit such as 2x8GB 2666MHz.