"while installing new system on my other computer. Installation got stack on remaining 23 second and its like that for one 20 min. What should I do with it?"
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Wait then Restart:
Give it a few to update. If no success in 10 minutes, restart the Mac. If a restart does not work, the. resin tall the macOS from Recovery Mode, or restart from a Time Machine backup you made prior to this update.
Reinstall the macOS:
Nothing would be deleted. It's just that items that have become corrupted or deleted, would be replaced or reinstalled back to where they should be. The expectation is that it will all be installed to how it should be. Go Here: How to reinstall macOS from macOS Recovery - Apple Support.
Learn from This:
Be certain to always create a backup of your Mac prior to making any major change to it (i.e update installation). That way, you can have something to restore from the Mac from, should anything go wrong afterwards.