Conversion of apk files to rar file format

As far as we know, there is no realistic purpose to perform apk to rar conversion and actually no way how to convert APK to RAR directly. Should you wish it, you could theoretically extract the APK (it's a renamed ZIP) and compress it in RAR (With WinRAR, 7-zip or whatever), or even compress the APK itself.  Just keep in mind that by doing this, the resulting file won't be useable for installation purposes in Android phones or devices anymore.

Open APK file    Open RAR file