ok, you have R version 3.6.1
so packages needing R4 wont work (unless you upgrade your R)
https://cran.r-project.org/web/packages/RODBC/ChangeLog
says that R4 is required since Version: 1.3-17 (2020-05-11, released)
you'd be able to install Version: 1.3-16 (2019-09-02, released) if you stick with your R version.
you can either find an MRAN mirror , or perhaps use renv package to install 1.3.16
If you had renv you would do
renv::install("RODBC", type = "binary")
I'm still on R 3.6.2 myself, and this is the result:
Retrieving 'https://cran.rstudio.com/bin/windows/contrib/3.6/RODBC_1.3-16.zip' ...
OK [file is up to date]
Installing RODBC [1.3-16] ...
OK [installed binary]
* Copying 'RODBC' into the cache ... Done!