I booked a train ticket on the Yeswantpur (Yeshvantapur, YPR) to Pondicherry (Puducherry, ODY) route. I gave my boarding point as Hosur. My reservation is from Yeswantpur. Am I entitled to board at Banaswadi (BAND) or Krishnarajapuram (KR Puram, KJR)?
Yes, but you have to inform IR at least 24 hours in advance, otherwise you may lose your seat.
See this answer: Boarding point change for an Indian rail reservation