You can install the newest release of Revit without uninstalling previous releases as multiple Revit releases can coexist, side-by-side, without issues.
When installing multiple release of Revit, it is recommended to start with the oldest release, including updates and hotfixes specific to that release, and end with the most recent release.
Deployments: When creating deployments for a new release of Revit, do not use a Revit.ini file from a previous release. The new release may require additional Revit.ini settings, which may not be defined in the file from the previous release. Missing settings may interfere with the proper functioning of the software. Instead, use the new release of Revit to define options from the user interface. This process generates a new Revit.ini file that you can use with the deployment.
Revit Models: When existing Revit models are opened and save in a new release of Revit, the files are upgraded to a file format that is specific to that release of Revit. When existing models are opened and saved in a new release of Revit, the models are upgraded to the new release file format. Once a model is upgraded, it can no longer be opened in a previous release of Revit.
Revit models are not backwards compatible. When you create or modify a model using a new release of Revit, you cannot open the model later using a previous release of Revit. As an example, if a Revit 2021 model is modified in Revit 2022, this model can no longer be opened in Revit 2021.
NOTE: To reduce the potential of inadvertently upgrading Revit models, it is not recommended to open Revit models from File Explorer, which open models using the latest release of Revit installed on that workstation.