You'd be hard pressed to get a playable fps on med with those specs. For a start the 7660g only has 512mb of video memory which is the minimum requirement for R2TW (Although apparently the game is optimised to AMD GPUs). Secondly R2TW doesn't really support quad core cpus and AMD cpus are not optimised for R2TW either, Although the cpu will still run it.
So no you can not run R2TW on medium with those specs (at least not with a playable fps) but you will still be able to run it on low with a decent fps.