Xcode project not showing list of simulators

Make sure that the project you are trying to run has deployment target equal to or less then the SDK version of your Xcode. In my case I tried to run a project which was built using iOS8.4 but I have Xcode6.1 with SDK version 8.1

I changed the deployment target to 8.1 and it start showing me simulators.

P.S before doing this, make sure that your code and external libraries are compatible with your new deployment target, else you have to update your Xcode.

I could not find any solution that would fix my issue. All simulators were there for all projects but the one that I needed them.

Solution:

Build Settings -> Architectures -> Supported Platforms:

changed from iphoneos to iOS

Try This, It worked like a charm! for me,

Follow below step

1) Clean Derived Data as show below,

 rm -rf ~/Library/Developer/Xcode/DerivedData/

OR

 Xcode---> Preferences--->Location--->Derived Data

2) In Deployment Info change Deployment Target

It's equal to or less then the SDK version of Xcode

3) Quit Xcode

4) Reopen Xcode you will see list of simulators

Hope this answer will help for someone.