@TBOne. Thank you for the quick response. Okay..
I am referring this manual
According to which, I have installed
(1) Installed a current version of vim (version 7.3 or higher). Most Unix/Linux operating systems come with vim pre-installed.
(2) Installed a recent version of the R software.
(3) Installed a recent version of tmux (version 1.6 or higher)
(4) Downloaded the screen.vim plugin and then install it from within vim and extracted as instruced
(5) Installed the latest version of Vim-R-Plugin from Ubuntu software centre.
The next thing mentioned is to just edit an R file in the vim and press F2 key or type \rf. The expected thing to happen after this is opening of an R console. The tmux window is supposed to split with an R console window in the right pane which is not happening.
The section of my ~/.vimrc says
let vimrplugin_vimpager = "no"
" start R with F2 key
map <F2> <Plug>RStart
imap <F2> <Plug>RStart
vmap <F2> <Plug>RStart
" send selection to R with space bar
vmap <Space> <Plug>RDSendSelection
" send line to R with space bar
nmap <Space> <Plug>RDSendLine