Basically I ran my project into iOS 10 and copied the .app from there and tried to run it on iOS 8 simulator on a different machine but its not getting installed.
But ideally it should get installed and run perfectly.
so ios 10 simulator .app is compatible with only iOS 10 for iOS 8 we again have to run it on iOS 8 simulator and copy it over
can anybody put some light on this problem
You need to set the app's deployment target appropriately and properly handle the usage of API that is not available in the oldest OS that you intend to support.
There shouldn't be any problem I have never experience this and I was able to run the app on iOS 8,9 and 10.