Re: What flower for bride’s hair?
I wore 2 roses on my hair during my reception. We bought them Friday…kept them in the refrigerator overnight. When the hairstylist put them on my hair, she also sprayed TONS of hairspray on them. They lasted all night without any issues (halfway through the reception, 1 of my friend hairsprayed it again just to make sure…lol).
Whatever flower you choose, please do NOT get fabric ones! They’re on your hair and all your guests will get a upclose view of them. Fabric flowers will look tacky. Stick to fresh ones. 
As far as how many flowers will look nice…that’s something you should discuss with your hair person b/c it will depend on your face, the specific hairstyle etc. In my case we bought a dozen roses. I told my hairstylist to take however many she wanted. She took 2. We saved 1 for my husband’s suit. And the rest, we put on my case as decor. And yes, all that was planned…lol.
For what its worth…it sounds like you’re going for a traditional look (you mentioned dupatta on your head). If so then I think you should stick with roses since it’s classic. You can’t go wrong with them.