class TestSuite(models.Model):
     test_suit = models.CharField(max_length=30)

class TestCase(models.Model):
     test_case= models.CharField(max_length=30)
     test_suit= models.ForeignKey(TestSuite)

[] TestSuit1: <- Item of TestSuit
[ ] Test_case1 <- Item of TestCase
[ ] Test_case2 <- Item of TestCase
[ ] ...

[] TestSuit2: <- Another item of TestSuit
[ ] Test_case3
[ ] Test_case4
[ ] ...