You can try to add quotation marks and make sure your package could support on your current R version, for example:
install.packages("aod")
I successfully installed "aod" package on the R 3.3.1. If this is the packages you are trying to install the same package, it should work fine for your R version.
If you want to install some open source software for bioinformatics from Bioconductor, please follow the instruction here.
## try http:// if https:// URLs are not supported
source("https://bioconductor.org/biocLite.R")
# Install specific packages, e.g., “GenomicFeatures” and “AnnotationDbi”
biocLite(c("GenomicFeatures", "AnnotationDbi"))