To Create and add multiple channels on YouTube using same email id in your existing YouTube channel follow the below given easy steps.
Open a Browser.
Login to your Gmail Account.
Open your YouTube Channel
Click on your profile picture at top right of the screen.
From popup Menu click on YouTube setting icon next to Creative Studio.
In new Open page find and click on Create a New Channel.
In new page opened Name your Channel.
Select the category of your channel.
Click on Check Box next to "I agree to page term".
Wait.
In few seconds you have your new Channel.