Please read through the FAQ section on here (link is over on the left) as well as all the messages in the Rookies section on here as the same question has been asked and answered hundreds of times.
The "courses" you need is nationally recognised technical qualifications such as Higher National Certificates, City and Guilds etc. (or whatever the equivalent is in your country) and hands on technical experinece, in either electrics, electronics or hydraulics.
Doing a one off course from any of the ROV "training schools" on its own will NOT get you a job.
As to who is hiring? No-one knows, everyone keeps asking, companies take people on as and when they feel like it, you have to be in the right place at the right time. And if you are going to ask me which companies I would say you have not bothered to go and find out yourself. The Internet has a lot of information, too many people want it all to be handed to them, make some effort and find out for yourself.
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