Rasakaka is correct.
He got NOC to join another company on its own new visa but the current company will cancell his RP and the employee has to leave qatar and he will be exempted from 2 years ban due to that NOC.
This is to be confirmed that paying 500Qrs one may not require to leave country.
NOC means no objection to join another company on its own visa. and 2 years ban will be lifted due to NOC.
Change of sponsorship means the the releaser will have the visa and the company will loose one visa and the 2nd company will gain one visa.
wishing best of luck.