I deleted one of the Organization Unit from my windows server 2012r2,but now i want to restore it how i can i restore it,is it possible through LDP or something else.
If you enabled AD Recycle Bin before, you can restore the OU first, then all the objects. Here is a step by step tutorial.
Basically, you need to restore the OU:
Get-ADObject -filter 'msds-lastKnownRdn -eq "MyOUName" -and lastKnownParent -eq "DC=MyDomain,DC=com"' -includeDeletedObjects | Restore-ADObject
And then the objects:
Get-ADObject -filter 'lastKnownParent -eq "OU=MyOUName,DC=MyDomain,DC=com"' -includeDeletedObjects | restore-adobject
If AD Recycle Bin wasn't enabled, you have to restore from a backup.