Bash not recognizing packages installed using pip-3.6 I installed pip-3.6 using Mac Ports:

sudo port install py36-pip


Then, using this version of pip, I installed virtualenv:

sudo pip-3.6 install virtualenv


Now when I tried using virtualenv, bash isn't recognizing it.

PS: I didn't want to select pip-3.6 as pip because I have pip working with OS X's version of Python 2.7.
MacPorts may not have put things where you think, see here. Did the pip-3.6 command work? What do you get when you which pip-3.6? 

Have you considered Homebrew over MacPorts? pip3 comes automagically with python3.x with Homebrew. It also has a virtualenv package that is easy enough to uninstall if needed.