3 years seems like a reasonable timeframe to change things from Apples side.
Only if India is capable of creating what Apple needs at a reasonable price. This is not certain. There are two issues:
(a) Will the Indian government accept software/intangible value creation as acceptable for this accounting? Maybe they will, maybe they won't, depending on whether their goal is "modernize the country" versus "employ lots of people in manufacturing".
(b) Remember when Apple talked about why they don't manufacture in the US, they made a big deal about the networks of people and suppliers that were so easily accessible in China but not in the US. The same arguments holds, only worse, in India. Not only do you not have those networks, but you have vastly inferior infrastructure, starting with basics like transport and electricity, compared to the US.
Point is, India is not such a marvelous and profitable growth opportunity that Apple is going to lose money to stay in the market. My guess is if the Indian government keeps pushing this (and is not willing to be flexible on my point [a]) Apple will walk rather than continue. India is not China, either in the value of the market, or in the value offered to a manufacturer, and trying to legislate it so will not change that.