What is the relationship between Guangzhou CRRC and China CRRC?

It's okay. According to the information of CRRC Guangzhou and CRRC China, CRRC Guangzhou has nothing to do with CRRC China. The full name of CRRC Guangzhou is CRRC Railway Locomotive and Rolling Stock Sales and Leasing Co., Ltd. Although the name has the word "CRRC", it has nothing to do with them. China CRRC Group Co., Ltd. is a central enterprise managed by the State-owned Assets Supervision and Administration Commission of the State Council.