Why the rpm dance

@mohammad50033 3 words are just not enough to answer. You will need to add information if you are hoping for a workable answer. Details like the exact year, the engine size, the transmission type, what you have already checked, what you have already tried. There are 100's of possibilities that can cause your RPM to surge. Describe the symptoms. When does it surge? Is there any time it stops surging or is there any time it gets worse?