There is no such thing that there would be a separate certification for each country. Technology remains same in whatever country it is being used. The only difference could be different languages can be used like in China, Chinese in Japan, Japanese and in India it will be English. So there is not much difference from which country you appear for the Cassandra certification. So there is a common preparation material as mentioned below for every country. Check the below link for getting Cassandra certification preparation material?

1. Cassandra administration certification preparation material with question and answers. (Available)
2. Cassandra developer certification preparation material with questions and answers (Available)
3. Cassandra interview questions online version. (Available)
4. Cassandra interview questions audiobook. (Available)

1. Check Sample EBook (Interview Questions) 
2. Sample Questions of Cassandra Developer Certification 
3. Sample Questions of Cassandra Administration Certification

Please note that most of the places you would get certification preparation dumps which are with the wrong questions and answers and it can lead to failure in real exam. We have already gone through all the questions and answers from the HadoopExam.com and don’t find that questions with the wrong answers. As well as the quality of the questions and answers with explanation is superb. Which really justify the answers of the questions. Hence I would suggest you go with this material for preparing the Cassandra certification.