If you go to the File itself in InstallShield, right click Properties - then a dialog should come up with the choices. Near the top is the "Self Register" checkbox. This is assuming a full version of Installshield 2015 and a Basic MSI.
Now, I don't recommend self-registration as there can be a number of problems that can be encountered, but I believe that might be what you are asking about.
The better method is to extract the Registry data outside of InstallShield and then plug that data into the Registry node in InstallShield. This is much less problematic, but more time consuming. It all comes down to trade offs in many cases.
Microsoft does not support self-registration so it is an extension in InstallShield.
