For guests staying on site property and have early entry, is Ollivaders open to purchase wands to start interactive play throughout park? Or would we have to wait?

There is online delivery to India

You can expect to wait in line. Though the way isn't too long.

Once the park opens, Ollivander's experience usually takes about 15 to 20 minutes to open in Hogsmeade, less at Diagon Alley. But the shops where they sell the wands (Ollivander's in Diagon Alley, Dervish and Banges and Owl Post in Hogsmeade) are open as soon as the parks open.