No, you cannot start working in Turkey while your work visa or work permit is still under process. You are allowed to start work only after the work permit is officially approved by Turkish authorities. Working without approval is illegal and can cause serious problems. It may lead to visa rejection, fines, deportation, or future travel restrictions. Even if you are already in Turkey, you must wait for official approval before starting employment. Following the rules helps protect your legal status and future opportunities in Turkey.