Correct instalation


I recently installed ruby on rails through railsinstaller, I followed
instructions and supposedly should check which versions of ruby,
Git and rails using the following commands

Ruby -v showed version 2.2.4p 230
Git --version showed 1.9.4.nsysgit.2
Rails -v The system could not find the path specified

In some reading I found that rails is the same as gem, the truth is
I am confused because of it, in the article it pointed that I had to
update with a command like this and showed

Gem -v 2.6.8

Could someone please tell me if it is already installed correctly?

Thank you for response