We can create a new gemset to install a specific set of gems in it. In this i am copying an existing gemset into a newly created gemset.

1> To list the available gemsets we can type :

rvm gemset list

gemsets for ruby-2.2.3 (found in /home/taran/.rvm/gems/ruby-2.2.3)
=> (default)
   global

2> We will create a new gemset named sample_gemset

rvm gemset create sample_gemset

ruby-2.2.3 - #gemset created /home/taran/.rvm/gems/ruby-2.2.3@sample_gemset
ruby-2.2.3 - #generating sample_gemset wrappers........

3> Now we can copy any gemset into this newly created gemset. Suppose i want to copy global gemset into this newly created sample_gemset

rvm gemset copy 2.2.3@global 2.2.3@sample_gemset

Copying gemset from 2.2.3@global to 2.2.3@sample_gemset
Generating gemset wrappers ruby-2.2.3@sample_gemset...............................-
Making gemset 2.2.3@sample_gemset pristine........................................

4> We can verify that sample_gemset has all the gems of global gemset. For this i am checking the version of rails. It will now have the same version of rails which was present in global gemset.

rvm use 2.2.3@sample_gemset
Using /home/taran/.rvm/gems/ruby-2.2.3 with gemset sample_gemset

rails -v
Rails 4.2.0

4> If we want to delete this sample_gemset we can use

rvm gemset delete sample_gemset

Are you SURE you wish to remove the entire gemset directory 'sample_gemset' (/home/taran/.rvm/gems/ruby-2.2.3@sample_gemset)?
(anything other than 'yes' will cancel) > yes

Removing gemset sample_gemset......