Hi All,
Is there any undo option is there in unix same as recycle bin in windows?
no, unless your orgranisation has the tape setup
Yes, it's called "Having a backup" 
Other than that it's important to remember that UNIX/Linux give you a lot of power, but also a lot of responsibility.
undo is for wimps.
Dude..In Unix if you want to undo any changes its not possible..All you have to do is before making any changes take a backup and in case the changes needs to be reverted back..,just copy the backup data once again.....
In unix always creful before doing anyhting if u are removing anthing take the backup of that data.