@bhaskarns
Firstly, please be aware that the Parental Control is not available when the Deco is in Access Point mode, it is only available when Deco is working in Router mode. Check the below article for more details:
What’s the difference between Access Point mode and Router mode on the Deco?
If your Deco is working in Router mode but still no Parental Control setting on the Deco app, please check and ensure the firmware of all the Deco M5 nodes are up-to-date, you can check it on the Deco app for new updates, or you may download the latest firmware from the local official website:
Download for Deco M5
After that, please reboot the whole Deco mesh system, then check again if you can find the Parental Control settings on the Deco app.