RStudio is an IDE for R that can be run on Oscar.
Open the Open On Demand Dashboard by following this link. Select RStudio (under "Default GUI's"). Fill in the form to allocate the required resources, and optionally select your R modules. Finally, click the "Launch Session" button.
Plotting figures may not work within RStudio. If this is the case, save the plots to a file, and view them through the Open On Demand Desktop App. If plots are required for your task, launch RStudio through the Desktop App.
To learn about using the Open On Demand Desktop App, look here.