Hello,
Sorry for the delay due to the weekends.
Please, make sure you have checked all the server requirements before the installation – http://prntscr.com/jqit53 https://www.8theme.com/demo/docs/royal/
In your case, upload_max_filesize should be increased. Ask your hosting provider support about help with this.
If you have downloaded the whole theme package, you will find there such files after extracting: Royal_Theme.zip file which is the WordPress theme, Translation files folder, Documentation folder, Patterns, PSD folder, Files for import. Choose Royal_Theme.zip file to install the theme via admin panel.
Regards