this() can be used to invoke a constructor of the same class
whereas super() can be used to invoke a super class constructor.

this() should be first statement in the constructor of the 
same class and you cannot call this() in other places

Super should be used only in the sub classes and super() is 
used to point methods of super class. where as this can be 
used in both super & sub classes and this() used to point 
methods in the class where it is called.

super is the first statement of derived class constuctor.

class room
{
 int l,b;
 room(int x,int y)
 {
   l = x;
   b = y;
 }
 void area()
 {
   int a;
   a = l*b;
   return(a);
 }
}
class studyroom extend room 
{
 int h;
 studyroom (int x ,int y, int z)
 {
  super(x,y)
  z = h;
 }
 int volume()
{
  int v;
  v = l*b*h;
  return(v);
}
} 
class sup
{
 public static void main(String args[])
{
  int ar,vol;
  studtroom s=new Studyroom()
  ar = s.area();
  vol = s.volume();
  System.out.println("the area is = "+ar);
  System.out.println("the volume is = "+vol);
}
}

1)Super() always calling the constructor of immediate  
super  class, super() must always be the first statements 
executed inside a subclass constructor.

2)You cannot use this() and Super() in the same constructor.