So, what are the exact official 4 rules? and Whom are they set by? NRA?
The Four Rules are attributed to Jeff Cooper and taught pretty universally, including by NRA-endorsed instructors.
Although some people refer to them as "Rule 1," "Rule 2," etc., the order doesn't really matter.
1 - Treat every gun as if it is loaded.
2 - Never let the muzzle point at anything that you don't want to see destroyed.
3 - Keep your finger off the trigger until you are on target and ready to fire.
4 - Be certain of your target and everything around and behind it.
As you think about the rules and their application, you see a built-in redundancy that keeps people safe.