Trading is not the proper word I believe in this context as it refers to all kind of activities in an economy. Exchange of bitcoins was never illegal. Exchange refers to what we call in general terms investment in bitcoins. Here you buy bitcoins using your local currency at a fixed rate of the former and sell the same at same conditions at the same or different rates,so you are not manipulating the official currency in any way as ultimately the crypto is again converted back into the currency that the economy uses. Also in 2020 RBI has approved to buy lite coin