[Ballu Miaa]

Create a Global variable

pawn Код:

new CountCPplayer;

Use it under OnPlayerEnterCheckpoint callback!

pawn Код:

public OnPlayerEnterCheckpoint(playerid)
{
    if(//Check for right cp id for the player over here)
   {
       if(CountCPplayer >= 5)
       {
            // Do what you want to do for 5 players here!
       }
       // set this var to +1 everytime a player comes in this checkpoint
      CountCPplayer++;
   }
}