Just a couple of cautionary notes, hopefully they will not be discouraging, just wanted you to be aware of them/not taken by surprise. You will likely have to pay a hefty customs fee as well, which very irritatingly they charge after the package arrives. Ie; they wont release it to you until you pay. It is assessed on the cost of the package *plus* postage (which also sucks) at some percentage which I frankly don't understand how they assess.
I am ashamed of how much I spent on my stuff in a country with so much need and don't really want to admit it (in my defense, it is my only hobby, it will keep me going until I get back to the US, maybe a year+ and I spend little on anything else) but am going to give you the totals so you can plan/estimate better. My total cost from NEC on my last package, including postage, was $387.00. Customs charged 16k INR on top of that, so about $220 more. I was shocked at the customs fee, I think I would have ordered less, or at least differently, if I'd been expecting it. And they held the package hostage at the office until I paid it (again, without refrigeration!) so I just went ahead and did.
Which is why I still think you might want to check with other Indian cheesemakers to see if they have advice for you. I hope they would be kind and smart enough to know that working together is good for everyone. Although I have no interest in commercial cheesemaking, in a country like India it makes sense for smaller makers to work together to find/create cheaper but good domestic sources for rennet and cultures, or maybe international sources with reliable products but less punitive customs agreements in place if there are such things.
Also, if you are ordering rennet, I agree powdered/tablet is safer. My package took three weeks to get to me (but in Kerala, I think yours will be faster) and my liquid rennet is a little wonky, I don't know if that is because it was held in high storage temps at PO facilities all that time but suspect it is possible. I haven't tried the tablets yet, but from all accounts they are less susceptible to temperature issues, within reason.