To do Alt + J I L on Mac in Excel, download and install Accelerator Keys, then press Option, followed by J, I, L.
Command: Lasso Select
This is how to do Alt + J I L 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 + J I l activates the Lasso Select tool. This tool allows you to draw a freeform selection around ink and drawn objects. Once selected, you can move, resize, delete, or apply other operations to the selected ink content.