There are many ways to buy bitcoins, and some of them are available in almost every country in the world. At your service are gift cards, bitcoin-ATMs, local traders, brokers and stock exchanges.
Which stock exchange sells Bitcoin. To my knowledge it isn't listed on any stock exchange till now
By the way, I buy from local exchange that allow me to directly buy for fiat money (Indian Rupee). The fees is negligible and I can buy instantly using Net Banking. It has become easy process to buy/sell Bitcoins in India now.