Dear Kavita, online coaching are very much popular these days. They provide you the freedom to study at your own pace and convenience. Medical is a vast field with endless information & it is very difficult to buy a new book every time, you can use online references to update yourself with latest findings. Online portals also provide a lot of useful content for medical entrance exam preparation, you can join anyone of them. As per my personal experience I will suggest MyPGMEE, as it is the best trusted online portal for pg medical entrance exam preparation.