Better to change in India now. They just changed the Indian note 2000inr note. If u got some old note, u cannot use in India. If u use the old note to change back to hkd (e.g.), u can change back only half of the value as the shop need to move the note back to India to change. (Actually maybe the deadline is over, should be on end of dec).
To play safe now, change in India. Now is 非常時期.
If u google, u can see lot of news about this. This is a really crazy idea that suddenly announce all 2000 notes (most commonly used note in mkt) is invalid.