According to the DeployR documentation each session is locked down:
"By default, R sessions executing on the DeployR grid are not authorized to access files or directories outside of the R working directory"
However, I have been able to upload a simple script using a user that has Basic_User role and that reads a file from the c:\ drive on windows.
t <- read.table("C:\\MyFile.csv")
t
How do you lock down access to the file system? I seem to have missed something.