> Could someone suggest me a way to install Pascal on a Mac running El
> capitan with XCode 7 IDE?
Download the installer from
http://www.freepascal.org/down/i386/macosx-netherlands.var and follow
the instructions on that page (the ones for 'Xcode 5+ compatibility'
and 'Unknown developer" error when installing (Mac OS X 10.7 and
later)'. That will install the compiler. It will not make it usable
from within Xcode itself.
While you can use FPC from inside Xcode, it's not recommended because
Xcode is on the one hand overly complicated and on the other hand has
very little to no Pascal-specific support.