Starting August 1, 2019:
All new apps and app updates that include native code are required to provide 64-bit versions in addition to 32-bit ver
This is an official blog post from Embarcadero about Delphi 64bit. You can request an extension to the 64-bit requirement, as follow:
Official Post From Sarina DuPont:
As you’re probably aware, starting August 1st, 2019, applications in the Google Play Store must support 64-bit. We are working to provide 64-bit Android support in RAD Studio, but in the meantime, Google’s Play Store team is considering extensions to the 64-bit requirement for our Delphi and C++Builder customers on an app-by-app basis (see steps below).
To ensure your C++Builder or Delphi Android 32-bit application is accepted into the Play Store, you will need to submit a request for an extension after following the regular Google Play Store publishing steps in the Console.
Note: Starting August 1st, 2019, only app updates to existing Android 32-bit applications will be considered for an extension by the Google Play Store team, not new 32-bit Android applications. For new Android 32-bit applications, it’s recommended that you submit them as soon as possible and start asking for an extension now, so that you are not impacted by the deadline come August 1st.
How to request an extension:
1) Visit https://support.google.com/googleplay/android-developer/contact/publishing
2) Fill out the form and select ‘I submitted a new app or app update but it is not live’
3) In the feedback field, indicate that your application was built with Embarcadero Delphi or C++Builder, and that you’d like to request an extension to the 64-bit requirement
Embarcadero customers can submit extension requests for Android 32-bit app updates to existing Google Play Store applications until August 2020.
It's impossible to compile a 64bit Android app with RAD Studio 10.3.
Android 64bit support is only available in RAD Studio 10.3.3 and later as can be seen from the August 2019 Roadmap. So you'll need to get RAD Studio 10.3.3 if you want to compile an Android 64bit application.
This also depends on if the you are using C++ or Delphi, it looks like C++ support for android 64 bit won't be available for at least a year.
It's not possible at the moment unless you update to Rad Studio 10.3.3.
However, here are some alternative (aggressive) solutions :