Convert ZIP to AAR

Alas, we do not have any useful information about any possible zip to aar conversions at this time. It appears that some files with arr extension do indeed exist, however it doesn't look like they can be created from ZIPs. It might also be very well possible that you have been in fact looking for zip to rar conversion, which describes repacking of ZIP archives to RAR format.

Simply put, it is impossible to convert ZIP to AAR directly.
Thus, there is no so-called zip to aar converter or a free online .zip to .aar converter to be found.