How to create a redirect for specific domain?
You can do this by using Domain Redirect module.


  This module allows the creation of an internal Drupal path that will
  direct the user to a unique path based on the domain that the user is
  in. The link is based at the path "/domain-redirect/12345" where
  "12345" is the redirect ID that is stored in the database.


OR

Try to use Domain Default Redirection module.


  This small module provides a redirection feature instead of providing
  the default domain contents in the Domain Access suite.