Solved!
1- Log into your MacBook pro (or iMac....)
2- Click on Apple logo on top left corner on the Screen
2- Go to System Preferences ( a new windows appear )
3- Click on iCloud icon then it will prompt you to log in to iCloud on that window
4- Once you logged in, click on Account Detail on the left hand pane
5- Then click on Contact tab on top of the page
6- Under "Reachable On" section, select the email that you not require and then click "-" to remove the email
7- Click Done
8- Close the windows
This will sync your Reachable-On (Alias) contact on all your devices once you logged into iCould on other devices, i.e iPhone, iPad....