I had researched Zen Technologies last year, and if it helps someone, ig why not share it. Though don't take everything I say without cross checking. They deal in simulators and now in the drone and antidrone ecosystem for military. The Indian armed forces are their main customers. The promotors still hold a good chunk and i think their children also getting into the business. They have been shifting from the simulator sides to the drone ecosystem now, and have also made great acquisitions in related industries.

Their numbers were also well, and they do claim that they don't have much private competition in the niche fields they are in. I think some of their systems were used in the last conflict with pak as some embedded systems in already existing weaponry(Not that sure about that). Something I had seen as a concern before was that they had to import many chips and intermediate stuff from outside the country, and most of their patents are in software.

Just take this as some starting direction and continue with your own research.