There is no simple answer to this question. It depends on a variety of factors, including your natural aptitude for the subject, how much time you are willing to dedicate to studying, and whether you have access to good resources. That being said, it is certainly possible to pass SSC without coaching. Many students do it every year. If you are dedicated and put in the hard work, you can likely achieve success. However, it is important to keep in mind that the competition is stiff and coaching can give you a significant advantage.