Can I switch my Azure CSP customer from a different CSP partner to rhipe ?

A customer can have multiple subscriptions coming from the same or multiple CSP partners, but cannot transition a subscription right from one partner to another. A customer can choose to migrate resources from one subscription to another, but this does not impact the subscription rights owned by a partner. The migration involved is at the resources level and is similar to how a customer would migrate or redeploy resources from an Open subscription or EA to other channels.

For complete steps on requesting new CSP partner relationship to an existing customer under a different CSP partner, refer relevant contents here