I am sorry for your difficulties, I hope you can arrange things...

I am sorry for your difficulties, I hope you can arrange things to sell. I am also an overseas investor but I still invest in Australian stocks on the ASX and not OTC which I thought was to trade in unlisted shares. As far as I can see on RMS website and in the annual report they are only listed on the ASX. I see what you are trading is quoted at https://finance.yahoo.com/quote/RMLRF/chart?p=RMLRF and only has sporadic volume. It looks to me that this is just an alternative way to set up a manual transfer of shares for those who can not access the ASX. In this case you actually hold shares on the ASX and you just need a broker that can trade international shares. It sounds like your broker is not really very helpful, maybe you could contact some other brokers for help on this. I looked at this a while back and there were a lot of options and margins were generally better with US companies doing this.

So in summary... I think you actually one real shares in RMS that are traded on the ASX. You only need a platform to do the trade. You should check your holding information to verify this. You then only need to find a broker that will let you trade shares internationally.