Actually your overall application matters and not the score. Anyway the guys going to engineering or related subjects, the important thing is your quant score, u need more than 770 in quant and more than 550 in verbal for top ranking univs. thats what I have seen at many places. but u should also have super recommendations , sop, acads, and many other things like projects etc. so there is no point in taking GRE again!
And thanks again guys for all your best wishes.