The phrase "gat on right side of" can be replaced with several different synonyms depending on the context. One possible substitute is "gun on the right" which is often used in discussions of firearm positioning. Another alternative to this phrase is "opening on the right side" which is commonly used to describe entryways or access points. In certain contexts, "portal on the right" may also be appropriate to use. Lastly, "hole on the right" or "gap on the right" may be used to describe physical openings or empty spaces. It's important to choose a synonym that is clear and appropriate for the specific situation.