NEED GENUINE GUIDANCE: My dad is stuck with his ESOP stocks

Hi all, If someone can genuinely help, please please reply. My dad worked with a well known global brand for over 20 years in the middle east. We returned back to India in early 2000s. When he left, the company had issued some stocks for him. I think he had been getting dividend since then. I didn't know about that till he recently asked for help to liquidate it. I got in touch with the institutions mentioned in the dividend certificates. All those institutions were headquartered in the UK. They replied saying they have a list of countries within their jurisdiction and India is out of that. This to and fro kept going and the final answer I got was to get in touch with SEBI. But since this isn't an Indian stock market related problem, I'd been turned down whenever I tried contacting someone who's knowledgeable of SEBI. I'm not sure where to take it from here. My dad is over 75 yrs by now and he is sad that all of it might go to waste.