Drones present a big security challenge across the world. A Hyderabad-based deep tech firm has indigenously developed a state-of-the-art protection mechanism from unmanned aircraft systems of all kinds that could cover drone threats across the border with Pakistan, China and more. Uma Sudhir spoke to Kiran Raju, founder of Grene Robotics, who have developed Indrajaal, an autonomous drone security system, ready for use.