The term "On Hold" is self suggestive. This facility has been in practice for quite sometime now but their is no official confirmation about this. RPO Hyderabad is first to announce officially that passport applicants can avail "On Hold Appointment" thereby meaning that if you fail or couldn't produce the document on scheduled date at Passport Seva Kendra, then your appointment can be put on hold and according to your convinience you can bring them again for verification.
This will save a lot time especially when its not easy to get appointments. You don't have to go online for scheduling your next visit, you can schedule your next appointment then and there itself ( i.e. at PSK).
RPO Ghaziabad is also allowing on hold appointment. Its a good thing for us.