the only mother board from the h61 budget series that comes to mind that can overclock is the asrock h61m/u3s3 mobo. the rest most likely cannot overclock.
If you don't know what it does, then it's best not to try using it. You can damage everything in your computer by adjusting this, so it's best to leave it alone. As well, there really is no need to overclock a sandybridge i5.