The currency of China is called the Renminbi or the Yuan and the currency code is CNY.
The currency exchange rate is 1 USD = 6.64 CNY = 65 INR. It is most convenient to exchange your currency at the airport itself, however, you can also exchange money in other places in China. All banks offer the same interest rates, and thus you need not worry about where to find the best exchange rate if you wish to exchange at banks. You could also exchange your money at the hotel, but here the commissions are higher than other places and thus is not required. Exchange counters and kiosks are propping up at different corners of the cities, it could be kept as your last option if you are out of cash and wish to have some in hand. It is advisable to keep all your exchange receipts, in case you wish to change the Chinese Yuan to other currencies after your trip.