Understanding the Coexistence of 32-bit and 64-bit Oracle Clients

See notes 1243374.1 and 781432.1 in My Oracle Support, as documented in the documentation.

Pre-installation Tasks for Oracle Database Client

2.6.3 Independent 32-bit client software for 64-bit platforms

In Oracle Database 11g Release 2 (11.2) and later, 64-bit client software does not include 32-bit client binaries.If you need a 32-bit client binary on a 64-bit platform, you can install it from each 32-bit client software.

When installing 32-bit client binaries on a 64-bit platform, the installer checks for existing 32-bit software.

Please refer to:
If you are installing both 32-bit and 64-bit Oracle Database Client software on the same system, see notes 1243374.1 and 781432.1 in My Oracle Support:

https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=1243374.1
https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=781432.1

You can.
I think it's written somewhere on the Oracle home page, but you can do it by dividing the Oracle-based directory.

However, I remember that it was hard to find a 32-bit download path...
Also, I remember that the assembly version registered was different at 32bit and 64bit, but it didn't work properly.Some versions do not offer 32-bit versions.
The assumption is that there is no version specification for the 32-bit client, there is a 64-bit version and a version of the client, and that the newly deployed application will run in that version...

As I wrote earlier, I think coexistence was achieved by dividing the Oracle base directory (the dir name following the installation path c:\app\).

This is a memorandum from the previous environment, but for your reference...
https://www21.atwiki.jp/ohden/pages/726.html