We would also like to know difference between On-Premise and On-SaaS license and which one is more suitable for us.
The on-premise license is used in your environment. This means you download jsreport to your server where you host it.
The https://jsreportonline.net is SaaS where we provide you with running jsreport without a need to host it or update it. You just pay the monthly fee, but you don't have access to the jsreport system or HW configuration .
Based on this infrastructure need we would like to purchase the cost friendly license.
Every instance that is potentially facing production users/systems needs a license. In case you deploy to an environment where you scale (servers, pods,containers..) to multiple instances, it is typically better to purchase a more expensive scale license, because then you apply a single license key to all of the instances. In case you deploy just to a single jsreport instance, you can purchase a cheaper enterprise license.
Please find respective details here