M7824 With cCRT in Unresectable Stage III Non-small Cell Lung Cancer (NSCLC)

Inclusion Criteria: * Participants must have histologically documented NSCLC who present with Stage III locally advanced, unresectable disease (International Association for the Study of Lung Cancer Staging Manual in Thoracic Oncology * Participants with tumor harboring an Epidermal growth factor receptor (EGFR) sensitizing (activating) mutation, Anaplastic lymphoma kinase (ALK) translocation, ROS-1 rearrangement are eligible. * Participants must have adequate pulmonary function defined as a forced expiratory volume in 1 second (FEV1) greater than equals to (\>=) 1.2 liters or \>= 50% of predicted normal volume measured within 3 weeks prior to randomization. * Adequate hematological, hepatic and renal function as defined in the protocol * Contraceptive use by males or females will be consistent with local regulations on contraception methods for those participating in clinical studies Exclusion Criteria: * Participants with Mixed small cell with non-small cell lung cancer histology * Recent major surgery within 4 weeks prior to entry into the study * Significant acute or chronic infections including human immunodeficiency virus (HIV) or known acquired immunodeficiency syndrome, Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection and active tuberculosis * Chronic Obstructive Pulmonary Disease exacerbation or other respiratory illness requiring hospitalization * Active autoimmune disease that has required systemic treatment in past 1 year (i.e., with use of disease-modifying agents, corticosteroids, or immunosuppressive drugs) * Any prior systemic cytotoxic chemotherapy for their NSCLC or any antibody or drug targeting T-cell coregulatory proteins