I forgot the password for Folder lock version 6 can somebody help to recover.

Not going to happen... you are going to have to remember your password. Its something you should have written down someplace safe. Think back to passwords you have used in the past... maybe that will help spark your memory.

There is no backdoor, that would defeat the purpose for even using it.

Either that or contact the software developers and they might have a method of password recovery in the event of forgetting..