As-Salamu 'Alaykum wa Rahmathullahi wa Barakatuh, Supplications or Dua is an part of Hajj and Umrah. There are certain times when dua is more likely to be accepted by Allah as mentioned in various narrations of Prophet صلى الله عليه و سلم. There are various places during Hajj and Umrah where dua is accepted. Below are the few references.