Personally, I found the HE6 to be in a whole different class.
BTW, deepak. Do you have the older or newer version of the HE500? The old one has the unwieldy speaker wire for a cable and the plastic-backed, softer, larger circumference pads. The latest ones have a light, thin silver cable and stiffer, rubber-backed earpads.
I actually liked the older one better for sound. They had great liquid mids. The newer one has tighter bass and a smaller soundstage but loses the special midrange.