Is there any chane by any Firmware update will this support IOT network. OR Is this a hardware limitation of the version 1.2

Nobody knows. Tp-Link forum admin won't answer it directly and will always try to be neutral and advise to wait for further updates. Deco users are at the mercy of the engineers, they only release as when they like without timeline. The only way is to sell it off cheaply, or get a used one with a more recent newer hardware version. Also, a good lesson to learn before buying Decos, always research and refer to their latest firmwares for each model before buying.