F11 not presenting code of Macaulay 2 to the Emacs buffer in OSX
I solved the problem this way, thanks to Marc for demonstrating M2 and Emacs.

The file you are modifying in the above buffer needs to have ending *.m2

where notice the heading at the top and the highlighted code for showing that the code is getting read correctly.

by this way, Emacs determines which compiler it uses for the selected code. So

Save as File.m2

F12 opens up the M2 promth

F11 interepts a single line at a time


Wuoala, M2 works out of the box with Emacs, awesome.
Enjoy.