I need to know that does mesos master manage any state information itself such as number of slaves, frameworks or any information. Or does it leverage zookeeper for all information.
Mesos stores cluster data in memory and in a so-called replicated log. If you are curious, what exactly is persisted across Mesos master failovers, check the Registry protobuf. Everything else, e.g. allocation information, agents state, is restored from the cluster via re-registering agents and frameworks.
Zookeeper is used for leader election only, Mesos does not store there any data. However some Mesos frameworks, e.g. Marathon, may use Zookeeper as persistent storage. Such Zookeeper cluster is often configured separately to avoid any interference with Mesos.