Dear Ajmal
I would be interested to know what happens to the form after the employee completes it. Does it go straight to the manager?
I imagine employees will be prepared to give more critical feedback if appropriate if they know that the manager won't have the opportunity to read the form before they go.
The organisation I previously worked at had the Manager conduct the exit interview, which seemed like a realy bad idea to me. Nobody gave any kind of meaningful constructive criticism as a result, but later when meeting people socially, they would give plenty of detail about how bad the system/manager was .