If your previous employer can issue a NOC on your name you can comeback immediately.
If your previous employer cancelled you and filed a complaint (some do) then most likely you could be banned for re-entry to Qatar.
If you can not get a NOC; unfortunately you will have to wait for 2 years until being able to comeback again, but remember if the employer filed a complaint to the authorities you could be banned or blacklisted which adds a little burden to your chances of coming back.
If your previous employer can issue a NOC on your name you can comeback immediately.
If your previous employer cancelled you and filed a complaint (some do) then most likely you could be banned for re-entry to Qatar.
If you can not get a NOC; unfortunately you will have to wait for 2 years until being able to comeback again, but remember if the employer filed a complaint to the authorities you could be banned or blacklisted which adds a little burden to your chances of coming back.
Regards!