Noc - No Objection Certificate

[Apeksha]

my MIL is a central govt employee and we r applying for a visitor visa for her. she has NOC for possessing passport.

1. Should she get a NOC for visa ?
or for Travel? If so , is there any sample NOC????

2. should she present the NOC for travel during the visa interview or is it sufficient to submit the NOC for passport.

3. Should she get a leave sanction letter with the specific dates of travel mentioned on it when submitting for the visa interview????

Please reply as it is very very urgent.
thanks,