If you are using ModusToolbox then open the application project then you can go the device configurator where you can enable the required number of SCBs you require. I have attached a screenshot below for your reference.
If you are using PSoC Creator, you can refer the pinouts section in the datasheet which specifies as which SCB Block supports which communication components and use the required number of SCBs.
Does PSoC Creator 4.x support CY8C62x8 or CY8C62xA? These part numbers do not seem to exist in the device selector list and would be required to get 9 UARTs from the available SCBs.
Does PSoC Creator 4.x support CY8C62x8 or CY8C62xA?
>>No, you have to use the Modus Toolbox IDE
If you are using the CY8C62x7 series, you can use the UDBs to implement the UART.
Refer to this blog on how to port UART component to PSoC 6:
13 UARTs... thats cool... would you tell us what you are working on?
Are you using an RTOS?