Hi @enrique-cano!
I recommend to have a look at https://www.vaultproject.io/docs/internals/high-availability.html#design-overview
If you deploy multiple Vault instances on Kubernetes with the same storage backend, only one instance will be active and and that instance will handle all incoming requests. All other nodes are hot standbys which do accept requests from clients but will simply forward them to the active node.
Cheers,
Michel