I used the command prtHardInfo, two ipcam Hikvision the result was language = 1. At this point, what kind of NVR should I buy? N = Chinese or NI= international.
"language = 1" means EN/ML (English / Multilanguage).
"language = 2" means CN (Chinese).
But be aware that the language value may actually be from an overlay over the real region if the camera is running seller-modified firmware.
That's absolutely fine as long as you don't remove that original firmware by doing a firmware update. As some of the sellers warn on their product descriptions.
My personal recommendation is to buy the English version from a seller that honors the warranty and offers post sales tech support. The cams you can go multi-language if you want. Check out Nelly's. They have great post sales tech support.