Hi, welcome to FT.

It's hard to say which carrier is a fault here. If I understand the rules correctly, though, it would be 9W, since they operate the final leg, but I could be way off with that. Hopefully someone can give a more definitive answer.

Since you only have another week or so left in India by the sound of it, I would not file any complaint in India. 9W has offices in USA as they operate out of JFK/EWR. If necessary, I would wait until returning to the US.

If 9W have said they would offer you compensation, then I would keep trying with them. They should have provided a case number and tracking information for you.