we well come you in India, but I have one question. Though Hindi is official language, but many states still don't follow Hindi. The unofficial binding language is still English. If you launch your devices with Hindi, then you will be able to cover only half of India, but if you launch it with English, you will cover whole of India. Moreover, the way Xiaomi sells it's phones, you will like to have customers who generally buy the products online, this young online generation people love to communicate in English.
During later stages, when your Hindi software is ready, you float the devices with Hindi, till that time start capturing market with English.