English accents change a lot within India. Every region has its own way of pronouncing the letters and words. Sometimes it becomes difficult for a native speaker to perceive all these differences, thus making the colloquial form of Indian English bit hard to understand.
This is where neutralizing the accent comes into play. You learn to speak not the American or the British English, but the right way to speak the English language. You shed all your typical Indian pronunciations and learn to speak English that is neutral and easily understandable.