India’s defence sector is undergoing a decisive transformation aimed at self‑reliance. For decades, dependence on imports constrained readiness and drained resources, but today indigenous systems are steadily maturing. Strategic deterrence is anchored by the Agni‑V missile and Arihant‑class nuclear submarines, while the 2019 ASAT test showcased space warfare capability. Air power is strengthened by Tejas Mk‑1A and Mk‑2 fighters, Project Kusha long‑range air defence, and layered systems like Akash and QRSAM. Breakthroughs include the Hypersonic Technology Demonstrator Vehicle, D4 anti‑drone system, and NAVIC satellite navigation. Emerging technologies—directed energy weapons, micro‑satellite constellations, Netra Mk‑2 AEW&C, AI‑enabled battle management, loitering munitions, UUVs, and indigenous AIP—expand India’s reach across domains. Advances in AI decision support and high‑energy propellants further reduce reliance on imports. Challenges remain in funding and integration, but India is building a layered arsenal from ocean depths to outer space, ensuring strategic autonomy through indigenous innovation.