Welcome to JustAnswer.com! My name is DriveFast71(Ron) and I will do my best to answer all of your questions completely and accurately.
The SRS light is "Supplimental Restraint System" - aka- The AirBag System. Unfortunately, there is no way to know "for sure" what the problem is, without retrieving the "codes" from the computer. This could be anything from a problem in the seatbelts to an impact sensor. There are literally dozens of parts/sensors in this system that when faulty, can set this light. You will need to find a shop that has a scan-tool that can read these codes, as most "free" or "personal" scanners do not read AirBag codes. Once you have these codes, then you can more accurately and efficiently determine the reason why the light is on, and an estimate to make the repair.