IBM has supported 27 languages since Notes 5, and Simplified Chinese is one of them, so there must be a language pack in 6.5. As for the precautions, to be honest, there won't be much problem. The language pack mainly contains Chinese dll files, Chinese built-in database templates and Chinese help documents, and there will be no problems. As a person who has worked in IBM for three years, I can tell you responsibly that you don't know how many times this addition has been tested by testers.