Changing the tariff of a virtual server on RealHOST is free of charge and is available only for existing services (the service status is “Active”). If the VPS is in the “Stopped” status, then it should be extended before changing the tariff.
You can change the tariff for a virtual server only in the direction of increasing the tariff plan (this is a technical limitation).
The settings should be made in the hosting services control panel https://realhost.pro/control