One of the burner in my Westinghouse GHR795S Gas Cook Top is not working properly. It appears that tje nozzle thread has been damaged while servicing and is now coming with yellow flame and some noise. Is there any way I can repair this. It is so expensive to get a technician to even come and have a look as they are only interested in new installation.
Don't. Just don't.
Find someone who is qualified to work on gas appliances safely.
There's a chance whoever has "serviced" the appliance has damaged the thread.
Maybe ask the person who did it what their qualification is and ask them to sort out what they've done.
We may have found other answers which could help you.