inbuilt camera is missing

Hello madhavath.

Thanks for reaching out to Apple Support Communities. We understand that you do not see the the Camera listed in the Security & Privacy settings of your iMac. We will be glad to assist.

Let's reset the SMC first to see if that helps:

"

1. Shut down your Mac, then unplug the power cord.
2. Wait 15 seconds, then plug the power cord back in.
3. Wait 5 seconds, then press the power button to turn on your Mac."

How to reset the SMC of your Mac

Next, start up in safe mode and test.

If the issue persists, Contact Apple for support and service

Cheers.

Hi madhavath.

Glad to see that the in-built camera is all set. Check out this resource for your Bluetooth connectivity concerns: If you can't connect your Magic Keyboard, Magic Mouse, or Magic Trackpad to your Mac

Cheers.