Yes, RDP can be used to access a virtual machine (VPS) as long as the virtual machine is running an operating system that supports RDP, such as Windows. RDP can be used to remotely connect to a virtual machine in the same way as it is used to connect to a physical computer. You will need the IP address of the virtual machine, and the login credentials of a user that has permission to remotely access the virtual machine.
You can also use a Virtual Network Computing (VNC) protocol to access the virtual machine's console directly.
It's important to note that the performance of an RDP connection to a virtual machine may be affected by the resources allocated to the virtual machine, such as CPU, memory and disk space. To have a better performance, you should make sure that the virtual machine has enough resources to handle the RDP connection.