Here is the journey of retrieving that data.
Use the readRDS() function for .rds files or the sf package to load GeoPackages. Specialized packages like GADMTools can further streamline the process. download gadm data version 36 work
Simply drag and drop the GeoPackage or Shapefile into your workspace. The coordinate reference system (CRS) is standard WGS84 (longitude/latitude) . Key Considerations Here is the journey of retrieving that data