Follow these steps to add a (new) simulator
- Click the Simulator icon and open the list of simulators.
- At the end of the list there is the opportunity to add a new simulator " Add an additional simulator ." This will open the "Device and Simulator" window.
- Click the Simulator tab .
- There are three fields on the simulator tab.
- Click the '+' icon in the lower left corner of the window.
- Simulator name: enter simulator name here
- Device Type: select iPad from this drop-down list
- OS Version: Select an OS version from this drop-down list.
- Click Create
A new new simulator will be added to your simulator's parameter list.
Take a look at this snapshot to understand the flow of the above steps: 
And if there is no simulator / OS version in the list of simulators, you are looking for
- Click the Simulator icon and open the list of simulators.
- At the end of the list there is an opportunity to add a new simulator " Download Simulator ". This will open the Component window (from the Xcode settings β).
- Select / click a simulator from the list you need to download.
Take a look at this snapshot: 
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