i have a bmw 323I (1999) engine6 stick shift
I changed the main relay (blue and white )but it still don't start what can the problem be

There are many things that can prevent your car from starting and it is not possible for me to help you from cyberspace. You may have to get the car to a place that can determine what exactly is wrong. The 1999 car can be scanned for faults to help determine what the problem is. Repost with this information and I will help you. Dr. Hagerty