Very envious of your 6 week shoot. Never done India, but shot China many times. Remember that just because you have glass with you doesn't mean you must carry it everywhere. Presumably you will be in hotel or some more or less secure place? I'd bring **minimum** 24-70 II, 50 1.4 or 1.2, and my workhorse 70-200 2.8 (I never ever leave home without that.) I'd consider the 16-35 II. I lilke my 135 f2; light and sharp. Bring 2 LaCie USB-powered external drives, a spare charger for your batteries (bring 3 batteries not 2); and ... make arrangements with someone you really really trust to dropship you another body if yours craps out. I never go overseas without at least 2 bodies and a P&S backup. Bring Imodium too.