In Indian railway reservation, while reserving tickets, we can select a particular station as boarding point (we can chose a from, a to and an optional boarding point). The boarding point indicates that we are going to board the train from that station only even if we have a reservation from a previous station. This prevents the Train Ticket Examiner from giving the seat to some other person until the station after the specified boarding point.

My question is, can I board the train before the specified boarding point if I book from there?

Not a dupe of Boarding point change for an Indian rail reservation. I am aware of the feature to change boarding point. But while chart prepared, it is impossible to change it.