[suhrab_mujeeb]

Use timers, for example:

pawn Code:

// Top of your script
forward GameModeChanger();

pawn Code:

// Under OnGameModeInit
SetTimer("GameModeChanger", 1500 * 1000, false);
// SetTimer(function, interval, repeating);

pawn Code:

// Bottom of the script
public GameModeChanger()
{
    SendClientMessageToAll(-1, "Map changing don't go anywhere");
    SendRconCommand("changemode YOUR_OTHER_GAMEMODER_NAME");
    return 1;
}

Though if it is done from a single gamemode it would be better.