Explore the concept of Black Hole Index derived from Gravitational Path Integral in this 47-minute lecture by Ashoke Sen at the International Centre for Theoretical Sciences. Delve into advanced topics in quantum gravity, including the AdS/CFT correspondence, quantum information theory, and black hole physics. Learn how these fields intersect to provide new insights into spacetime emergence, quantum error correction, and the black hole information paradox. Examine the application of quantum information tools to long-standing problems in quantum gravity and discover how black hole physics informs our understanding of information scrambling in chaotic quantum systems. Part of a comprehensive program on Quantum Information, Quantum Field Theory and Gravity, this lecture contributes to the multidisciplinary exploration of quantum gravity, quantum information theory, and many-body physics.