To do Alt + P R S on Mac in Excel, download and install Accelerator Keys, then press Option, followed by P, R, and S.
Command: Set Print Area
This is how to do Alt + P R S on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + P R S sets the currently selected cells as the print area. Only the cells within the print area will be printed, making it easy to print specific sections of your spreadsheet without printing the entire sheet.