Installment plans are recent trend isn't it. I see previously it was 2 year contracts for 199 etc. emi are common in India as well. Apple could have done the same in India.
In India, you'll typically buy your phone outright based on what features you're looking for (Dual SIM, OS version, Storage, etc). Hence manufacturers/retailers typically offer a EMI plan for top-end phones (think Samsung S7, Apple iPhone 6, etc) since the outright cost is quite high.
Then you'll decide which carrier you want to use based on the tariffs they're offering (Voice Calls, data, SMS, etc.)
Although carriers do offer phones with their plans, it's rarely ever bought in that manner.