How to promote safety culture in organization where no safety policy exist ?

Management commitment is crucial for a safety culture. This means that every single manager, from CEO to mid management has to take safety seriously and take the decisions they need to make in their work with safety of all people in mind. Without management acting and standing behind safety, a safety culture can simply not exsist. 

You can win the goal by slow and steady method. Just post the safety charts near the work areas and start a short time lectures at the site. Then after a suitable time you can start a vast level safety seminars or lectures at project level.