Hi Vaishakhi,
I got your files, thanks.
Unfortunately the list template has no data and when I try to add an item to it it throws an exception related to a Nintex workflow.
Event manager error: Could not load file or assembly 'Nintex.Workflow, Version=1.0.0.0, Culture=neutral, PublicKeyToken=913f6bae0ca5ae12' or one of its dependencies. The system cannot find the file specified.
Regardless the error, I created a similar configuration (doc library, qListForm and FCB (form component behavior) and everything works ok for me.
I'd suggest you to create a new doc library and try again from scratch to see what happens.