A Study to Assess the Safety, and Tolerability of Nivolumab + Relatlimab Fixed-Dose Combination (FDC) In Unresectable or Metastatic Melanoma Participants In India

Inclusion Criteria \- Participants must have an Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 1/Lansky Performance Score ≥ 80% for minors (ages 12-17) ONLY. Note: Participants with ECOG PS 2 are allowed if the performance status of 2 is attributable to disease burden (and not to significant comorbidity), and if the investigator and Medical Monitor agree the patient may benefit from treatment. * Participants must have histologically confirmed Stage III (unresectable) or Stage IV melanoma, per the American Joint Committee on Cancer (AJCC) staging system (8th edition). * Participants must have measurable disease by Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 criteria. * Participants must have completed prior radiotherapy at least 2 weeks prior to study treatment administration. * Individuals of Childbearing Potential (IOCBP) must not be pregnant or breastfeeding. Exclusion Criteria * Participants must not have active brain metastases or leptomeningeal metastases. * Participants must not have uveal melanoma. * Participants must not have an active, known, or suspected autoimmune disease. Note: Participants may enroll with the following conditions: i) type 1 diabetes mellitus; ii) hypothyroidism only requiring hormone replacement; iii) skin disorders (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment; iv) conditions not expected to recur in the absence of an external trigger are permitted to enroll. \- Participants must not have a condition requiring systemic treatment with either corticosteroids (\> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days of start of study treatment. Note: Inhaled or topical steroids, and adrenal replacement steroid doses \> 10 mg daily prednisone equivalent, are permitted in the absence of active autoimmune disease. * Participants must not have a history of myocarditis. * Other protocol-defined Inclusion/Exclusion criteria apply.