$ ./read_db.sh 
Department : CS
rank	name	mark
1	Navin M	98
2	Nawaz O	80
3	Kavya N	70

Department : EC
rank	name	mark
1	Hari S	80
2	Neenu J	70
3	Alex M	50
4	Bob A	30

Department : AE
rank	name	mark
1	Anu M	90
2	Sruthi	89
3	Andrew	89