After earning your Mcom from Ignou, you can pursue a career as a lecturer. However, you must also pass the NET exam to be eligible for a lectureship.
Whether you get your M.com from a distance learning institute like IGNOU or a traditional college makes no difference. You are still eligible to take NET. State-level exams are an alternative to the NET. Every state has its own set of exams. Passing a state exam qualifies you for lectureships only in that state. To be eligible to become a lecturer anywhere in the country, you must give the NET. Most people would instead pass state-level exams and work as a lecturer in their state. They apply for NET after gaining experience in their field.