Dear Matt,
I've never had a problem with X-rays, in and out of Delhi, Madras, Goa and Bangalore.
India is so vivid that anything will do, quite honestly: I'm currently shooting Sensia 100, as a modestly saturated and inexpensive good-quality film.
Are you sure you want both 35mm and 120? I've normally taken both to India but next time I'll leave 120 behind: too much hassle carrying both formats (and I've done it in the past with Hasselblad, Linhof and Alpa, and Frances has used Mamiya 645 and Alpa). Increasingly I take only one outfit, either Leica or Alpa, wherever I go, unless I'm testing gear for the magazines -- and then I'll usually drive (Central/Eastern Europe, Spanish Pyrenees, Portugal, South of France) rather than flying.
For spectacular geometrical compositions, don't miss the Jantar Mantar. For street photography -- well, there's the whole of India!
Where are you going apart from Delhi?
Cheers,
Roger