You can directly create a cloud product instance such as ECS, SLB or RDS under a specific VSwitch in the VPC console.
Log on to the VPC console.
In the left-side navigation pane, click VPC.
Click a region and then click the ID of the VPC where the VSwitch is created.
On the VPC Details page, click VSwitch.
Click Create an Instance for the target VSwitch, and click the type of instance you want to create.
Complete the instance configuration on the corresponding purchase page. After creating a VPC ECS instance, you can change the private IP address and VSwitch of the ECS instance.