How many sites can I install when I buy Porto theme?
Thanks for asking your question at Envato forum.
You are able to install your Porto theme only one domain as all of WP theme you are able to install one theme one domain.
In adddition if you need to install more than 1 site/domian then you have to buy license of the theme for each site/domian. In short each license will work for individual domian.
Thank you so much!