Hi @kanika chhabra ,
I suggest you start with the Windows 10 Update Troubleshooter over here:
Windows Update Troubleshooter for Windows 10
https://support.microsoft.com/en-us/windows/windows-update-troubleshooter-for-windows-10-19bc41ca-ad72-ae67-af3c-89ce169755dd
If the above doesn't help, continue onwards with the following troubleshooting steps:
Troubleshoot problems updating Windows 10
https://support.microsoft.com/en-us/help/4089834/windows-10-troubleshoot-problems-updating
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Best regards,
Leon