It will have a CPU list which you can see if the a6 will work.
The a6 is a pretty weak CPU. Can you try some non A series?
Not really sure if this is the right place to ask but basically, I don't know what hardware I need to buy. I know I have a gigabyte f2a78m-hd2 motherboard and a gtx 960 graphics card. I would like to try and upgrade my RAM from 8gb to 16gb, and possibly the amd a6-6400k 4.1ghz. The only thing is, I understand components have to be compatible with the motherboard, and I'm not sure if the power supply or fans will need upgrading in order to support tge new hardware. Any help is much appreciated