No. Only users from organizations that have a direct commercial relationship with Rancher are allowed to file tickets with Rancher Support. End-customers of MSP partners would need to file support tickets with the MSP partner, who is required to provide the first couple of levels of support to such end-customers. Rancher Support in such scenarios is only to the partner and not to the end-customer.
A partner can resell Rancher Support to any end-customer of theirs, as needed. In this case, the end-customer has a direct commercial relationship with Rancher and can file tickets with Rancher Support.