Problem
I checked there is no rmr2 package included.
Solution
First download rmr2_3.0.0.tar.gz from gitHub and then from your r terminal install.packages("/home/satya/Downloads/rmr2_3.0.0.tar.gz") at the place of satya you can write your user name.
Also you are advised to run update.packages before install.packages to ensure that any already installed dependencies have their latest versions.
Please refer to https://github.com/RevolutionAnalytics/RHadoop/wiki/rmr as rmr2 installation is slightly different.