Sure. Is there a way to reach PG? I can email and check with him.
Also, I picked this name as we decided to put up HN India in a HN meetup and also because HN conveys our objective well. We are not running this for profit.
In a lot of cases, the problem with using someone else's trademark isn't that you're profiting off of it (though that's not great either) - it's the resulting brand dilution/confusion that results.
If I didn't know better, I would assume that Hacker News India was affiliated with the original, which is a problem. HN would then be affected by any actions of HNI going forward, and no trademark holder wants to be put in that situation.
For the sake of respect, I would consider renaming your project.