Hey Everyone! I need to make a external system like custom website, or MERN stack website, and we need to integrate a website with NetSuite. So what is the best way to do this?

Pretty open question. There are lots of integration options so "best" might depend on desired functionality, available resources, skillsets, and other factors specific to your project. You can use SuiteScript to connect to external APIs, SuiteTalk to connect to NetSuite's API, RESTlets to create custom APIs, 3rd party tools.

Thanks👍