If you are using rvm and want to load project specific ruby version and gems automatically when you access the project directory, for this you can use a very simple command

rvm --create --ruby-version use ruby-version-number@gemsetname

example

rvm --create --ruby-version use ruby-2.2.0@findnerd

If you want the gems to be loaded from the global gemset then in that case

rvm --create --ruby-version use ruby-2.2.0

By using this command you wont have to use rvm command to load a particular gemset or ruby version and you can manage different projects running on different ruby and rails version simultaneously.

Behind the scenes

It basically creates two files -

1 - A .ruby-version file that contains the required ruby version "ruby-2.2.0"

2 - A .ruby-gemset file that contains gemset name in this case "findnerd".

which basically tells rvm to load the required configuration.

I hope this helps anyone trying to cope up with multiple versions of ruby,rails or gem versions.