//this uder your game mode
SetTimer("message",60000,true);

//now this anywhere in script
forward message();
public  message()
{
new ran,mes[50];
ran=random(5);//no. of messages u use in brackets
switch(ran)
{
case 1:format(mes,50,"Use /help to view how to play on server");
case 2:format(mes,50,"Use /cmds to view commands");
//like this continue till no. of messages filled in brackets of random
}
SendClientMessageToAll(-1,mes);
}

//Top Of FilterScript Or GameMode
#define MAXIMAL_MESSAGES 3

new LastMessage;
//Callback OnFilterScriptInit Or OnGameModeInit
SetTimer("Message",1000 * 60 * 10,1);
//After Callbacks
forward Message();
public Message()
{
    switch(LastMessage)
    {
        case 0: SendClientMessageToAll(0xFFFFFFFF,"First Message");
        case 1: SendClientMessageToAll(0xFFFFFFFF,"Second Message");
        case 2: SendClientMessageToAll(0xFFFFFFFF,"Third Message");
    }
    LastMessage++;
    if(LastMessage == MAXIMAL_MESSAGES) LastMessage = 0;
    return 1;
}

new RandMsg[][] =
{
    "Welcome to "Server Name"! Before you start your journey here, use /help and /tlaws to start you off.",
    "You can acquire licenses at our City Hall.",
    "Found a bug? Pleases immediately file a bug report at "Website"",
    "Stay updated on the latest news by checking the forum: "Website"",
    "Remember, this is not a DM server. Everything must be role-played appropiately.",
    "Please follow the server rules at all times. They can be found on the forum. ("Website)",
    "Found a player cheating/exploiting? File a complaint at once with (/report) to inform an adminstrator.",
    "If you are caught by the LAPD commiting a crime, you must role-play fairly & properly.",
    "Staff recruitment is underway. Please do not PM an administrator to join the staff team, instead check the forum.",
    "Hacks are NOT tolerated! Cheating will result in severe punishment.",
    "Create an application to join the staff team through our forum "Website",
    "Want to earn amazing privelages such as a V.I.P status? Donate Today, Enjoy Tomorrow.",
    "This is an Advanced-RP server. Use /requesthelp for more info.",
    "Donations are now ready! Please help the server survive by donating today! (Forum Tab).",
};

forward ShowHelp();
public ShowHelp()
{
    new i = random(sizeof(RandMsg));
    new string[128];
    format(string, sizeof(string), "Server BOT: %s", RandMsg[i]);
    SendClientMessageToAll(COLOR_LIGHTBLUE, string);
}

SetTimer("ShowHelp", 60 * 3 * 1000, 1);

#define GREEN      0x15FF00AA
new RandomMessages[][] = {
  "{FFFFFF}[Info]: {63F279}Like our server? Add us in favourite!",
  "{FFFFFF}[Info]: {63F279}To get more knowledge about the current commands, please use /cmds.",
  "{FFFFFF}[Info]: {63F279}You want to check your stats? use /stats [Your ID], you can check other's stats 
  "{FFFFFF}[Info]: {63F279}Use /admins to see the current online staff members.",
  "{FFFFFF}[Info]: {63F279}Spotted a hacker? don't panic, use /report [ID] [Reason] and let our staff team handle it.",
  "{FFFFFF}[Info]: {63F279}You want to help the server grow up? donate for us to keep us alive!"
  };

forward RandomMessage();
public RandomMessage()
{
SendClientMessageToAll(GREEN, RandomMessages[random(sizeof(RandomMessages))]);
return 1;
}

public OnGameModeInit()
{
    SetTimer("RandomMessage", 60000, 1); // 1 Minutes
    return 1;
}