it is not illegal to work as nurse but the problem is as per SCH guidelines, hospitals and clinics are not allowed to hire a medical staff without having applied the medical license. you can apply and work as long as your medical license is on the process but be sure that when you apply for the medical license, you have already enough experience to support your application. you can check the minimum experience required by the SCH in applying a medical license. www.sch.gov.qa. as what my previous post, only hamad hospital can hire a medical staff even without the medical license or prometric exam as long as you meet the minimum requirements of 2 years working experience.
sometimes, there is an options wherein the hospitals or clinics provide a training certificate for their applicant even though the applicant did not really train with them in order for the applicant to meet the rquirements of the SCH.