Want generate random time + random player

Hello ! Im french excuse me for imperfect english
I expose you my problem :
I want to generate a random number and recover num for random time
like that:
Random dice = new Random();
int max = 3000;
int min = 200;
int counter = min;
if (counter <= min) {
int num = 1 + dice.nextInt(max);
this.tornadetime = num ;

BUT I don't now how to make timer whith num
So what should I do ? Bukkit.scheduler.BukkitScheduler.scheduleSyncRepeatingTask how ?

Code:java

package Events;
 
import java.util.Random;
 
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.util.Vector;
 
import fr.blizzteam.hg.HungerGames;
 
public class Tornade1
{
    public HungerGames plugin;
    int tornadetime;
    public void tornade1(){
 
    if (plugin.begun) {
        Random dice = new Random();
        int max = 3000;
        int min = 200;
        int counter = min;
        if (counter <= min) {
 
        int num = 1 + dice.nextInt(max);
        this.tornadetime = num ;
 
        if (Tornade1.this.tornadetime == 10);
        Bukkit.getServer().broadcastMessage(ChatColor.RED + "Attention une catastrophe approche.");
        int random = new Random().nextInt(Bukkit.getOnlinePlayers().length);
        Player player = Bukkit.getOnlinePlayers()[random];
        if (Tornade1.this.tornadetime <= 0){
            Tornade.Effects.spawnTornado(plugin, player.getLocation(), Material.WEB, (byte) 0, new Vector(2, 2, 2), 200, 30, (long) 30*20, true, false);
        }
        }
 
    }
 
 
 
 
        }
 
}