So, i have an Cooler Master Hyper 2012 EVO Heatsink i only have one fan to attach it can i attach that using that particular one fan for it? please reply .. because i've seen ones with two fans what does that mean?
I'm not sure what you're asking in the beginning of your post, but when a 212 Evo has two fans on it, that means it's in a push/pull configuration. It helps increase airflow. It may also bring your CPU temps down a few degrees.
[Edit]
Oh okay, are you asking how to attach two fans to the heatsink? If so, then you'll need to find your 212 Evo's box with the accessories that came with it. They should have included some clips that resemble the ones on the fan that came with the cooler when you bought it. Attach those clips to your second fan, and then attach the fan to your heatsink. Make sure the fan is oriented correctly.