Update: Model is in fact famous Persis Khambatta [Thanks, Geetali! You are awesome!]. I had a hunch but didn't pursue it because of previous 'no she is not' experience.
It's incredible how her looks changed through the 60s - Miss India and 'Bombai Raat Ke Bahon Mein', 70s - the ads and then the 80s - the Star Trek head shave.
Update: Thanks to an anonymous tip-off (check comments) we have another (more probable) name - Yasmin Daji., who was crowned Miss India in 1966 by Persis Khambatta. Apparently this same image was used by Persis Khambatta in her coffee table book 'Pride of India' (1997).
Update: I checked that book and it is indeed Yasmin Daji. And this image is used in the book.