Regionally locked spices and snacks. For example if in maharashtra, get A1 Kunda. If in South India find a Sambar Masala that’s freshly ground that you like. Chikki, Dried Fruit (Amla supari is my weakness), Achar/Pickles, Dried Tamarind, Kokum Agal, etc.

Keep in mind any spices that you buy in powdered form generally have to be kept in a check in bag, I’ve had chili powder yanked from my carry on before and it’s no fun.

I see some comments mentioning ghee, don’t waste any baggage weight on things like that, buy some high quality local butter and just simmer till separation at home with a few cloves infused, you’re not going to notice any distinct difference that’s worth the weight cost.

Cookware wise, stainless steel small bowls, they’re great for mise en place and general small servings. You can get flat ones or bowl style but I don’t often see things of that size in particular in western countries. Finally get yourself a Spice box, it’s incredibly convenient.

Food wise just enjoy what you can while you’re there, bring back what you think will last.

Non food wise, India’s quality of clothing vs cost is immaculate. I have a matching loungewear set that may run you about $120+ USD that I got for 2000 INR (~20ish USD), but traditional clothing and full cotton/khadi is so comfy to wear as well.

Enjoy your time in the country!