Should there be an Apple affiliated authorized reseller with their own service
department, they may be able to help; at least in so much as replacement
hard drive or other work. Perhaps diagnostic testing and then repair.
Depending on which model MacBook Pro you have (build model sales year
and specification) the hard drive may not be hard to replace with new one.
Then you'd hope to have adequate bandwidth and access to download any
of the Mac OS systems that may have been capable of reinstalling in there.
Due to certain keyboard commands you may have options (still) such as
the original system the MacBook originally shipped with, may be available.
• About macOS Recovery - Apple Support:
Other details that should not be dismissed, are in this other page (+ links)
• How to reinstall macOS - Apple Support
At some point, you may not be able to re-install an older original macOS.
Once a certain upgrade level is attained, for some reason, things change.
You may be able to install a working system to an external USB drive;
the drive may need to have its own power supply w/ fastest connection
possible. Or whatever data port speed is higher that supports booting.
An authorized Apple independent service/repair and authorized reseller
should have people on staff that could help you; generally for customary
service fees, plus authentic or best quality replacement parts.
Sorry to not be of much help in this matter. I suggest you to start a new
topic thread so it won't be seen as 'solved' (as those get ignored after)
& perhaps be noticed by other helpful persons who're browsing through.
The links above cover most modern install and erase/reformat/reinstall
methods; in brief they can be enough if there isn't a hardware failure.
..PS: There doesn't happen to be a file vault or secure encrypted drive involved.?