Question: Lets say I already have a Kafka cluster working, should the Pinot cluster use the existing zookeeper which is used by Kafka or a separate zookeeper exclusive for Pinot cluster should also do the trick? Just that we provide the proper zookeeper URL in the table config is required?

Both of them works. In light weight usages, you can share ZK cluster. If the usage is very heavy, then you can have dedicated ZK for Pinot for better isolation.