You can find the version number of BlueStacks in any of the following ways:
From BlueStacks home screen
Launch BlueStacks 5 and at the top left corner of the home screen, right next to the BlueStacks logo, you'll find the version number of BlueStacks you're currently using.
From BlueStacks settings
Launch BlueStacks 5 and click on the gear icon on the Side toolbar to open the Settings menu. Click on the "About" tab and view the version number under the BlueStacks logo.
From BlueStacks Installation screen
After downloading a new version of BlueStacks 5, run the installer file. On the installation screen, you'll see the BlueStacks 5 version number you're installing, as shown below.
Thank you for choosing BlueStacks. We hope you enjoy using it. If you have any further questions, please contact us at support@bluestacks.com. Happy Gaming!