What means NLR? Give atleast 1 example situation.
It stands for New Life Rule, and an example of a player not following NLR would be if they had returned to a spot they had previously been RP killed (This excludes deaths due to RDM or Props) within a window of 5 minutes from the point of death. NLR is usually brought up during Raids.

Not fully correct, NLR states that you must not go back to the area(not point) of your death, and it is 3 minutes and not 5. You also must to 'forget' everything from your previous life.

What means RDM? Give atleast 1 example situation.
RDM stands for Random DeathMatch and an example of RDM would be if a player kills another player for no reason other than to see them dead, It is not considered RDM if a player kills another player in self defense, or if they are a hitman and kill another player whom they have been contracted to. RDM can also fall into two smaller categories of CDM and PDM, which stands for 'Car DeathMatch' and 'Prop DeathMatch' respectively.

Note that RDM refers to killing for no valid RP reason.