Hi Thushar,
That is most likely caused by a third party program causing the computer to crash constantly and in your case, to not being able to boot in normal mode.
When your Mac boots on safe mode it prevents third-party programs to load, so we can safely assume something you installed recently is causing the issue.
Go back to any programs you might have installed or updated recently, and either roll back the updates or uninstall them and see if that fixes the issue.
In any case, I would recommend backing up all the important data while you are on safe mode, so in case you can’t figure out what program is causing the issue you can reinstall a clean version of your OS.
Hope this helps!