Can we use this plugin on multiple sites?

Yes! As you know, WPBULKiT – Bulk Edit WordPress Posts / Pages Plugin is a premium product that is sold through the iThemeland store. For each purchase, you will be assigned a purchase code and you can use this purchase code on only one website, so to use the WPBULKiT – Bulk Edit WordPress Posts / Pages Plugin on your various websites, you need to separate license for each site.