It is because the Tropic Of Cancer passes through the middle of the country dividing the country into two somewhat equal halves.Those two halves are known as Sub tropical zone and Tropical Zone.This also helps India in experiencing two types of climate i.e sub tropical climate and tropical climate.It passes through Mizoram,Tripura,West Bengal,Jharkhand,Chattisgarh,Madhya Pradesh,Rajasthan and Gujarat. Hope it helps and pls mark as the best answer. :)