Older versions of Xcode for Catalina

I do not understand what you mean by intel 7 Mac, but the requirements of recent Xcodes are described here:

https://developer.apple.com/support/xcode/

Seems Xcode 12.4 is the latest Xcode which can run on Catalina. (You need to upgrade your macOS to 10.15.4 or later to run it.)

You can download older Xcodes through More Downloads pages.

Please remember, if you are planning to develop an iOS app for App Store, you can use Xcode 12.x only till April 2022.

App Store submissions now open for iOS 15 & iPadOS 15

Starting April 2022, all iOS and iPadOS apps submitted to the App Store must be built with Xcode 13 and the iOS 15 SDK.