In case your newly uploaded theme is not showing up, your first step is to ensure that the theme is uploaded in the correct location. The correct location is : wp-content/themes in your WordPress installation folder.
At times, themes get bundled in their own sub-directory and when you try extracting them, the files don’t get saved in the correct sub-directory, that is in wp-content/themes
For example, a theme called mytheme might be incorrectly located in
wp-content/themes/mytheme/mytheme
In this situation, you will have to put the theme files in
wp-content/themes/mytheme