NOC (No Objection Certificate) means you cannot transfer to any sponsor. NOC is only an aggrement that your previous sponsor will agree that he/she will released you or to work with the other company, if... the expatriates approve it also. but if the expatriates wont agree(base on how your old sponsor talks to the expatriates) then you have to wait 2 years to come back here in qatar. wish you luck, just be good to your boss.