@ArjunPrasad 

A Tapo H200 supports up to 4 SubGHz cameras or doorbells. 

You can search for the Tapo C420 on the local TP-Link official website. If you find an option for a single unit (rather than a kit), it indicates that this model is available for individual sale in your area.

Additionally, you can check the websites of authorized TP-Link retailers to see if the device is in stock. Keep in mind that different retailers have varying inventory and sales practices, so we are unable to provide accurate stock information. TP-Link Where To Buy