install.packages("Rdata")
#> Installing package into '/home/roc/R/x86_64-pc-linux-gnu-library/4.0'
#> (as 'lib' is unspecified)
#> Warning: package 'Rdata' is not available (for R version 4.0.0)
Created on 2020-09-11 by the reprex package (v0.3.0)
The message indicates that no package named "Rdata` is available from the CRAN repository of core and contributed packages. It is possible that a package of that name is in some other repository, but it would be necessary to know where.