Django multiple Forms in a single Form instance,validation error

Registration Form Consists multiple ContactForm and a FeeForm , i try to validate FeeForm,ContactForms existed in Registration Form,Validations are failed and it didn't display any Validation Errors ,For empty Fields of FeeForm, Contact Forms

forms.py

class ContactForm(forms.Form):
    address = forms.CharField(widget = forms.Textarea(attrs = {'rows' : '5'}),required = False)
    phone = forms.CharField(required = True)
    email = forms.EmailField(required = False)

class FeeForm(forms.Form):
    name_of_bank = forms.CharField(required = True)
    dd_number = forms.CharField(required = True)
    date= forms.DateField(required = True)
    amount = forms.CharField(required=True)
    def clean_amount(self):
        amount = self.cleaned_data['amount']
        if amount == '':
            self._errors["amount"] = ["Please Enter Amount"]
        return amount 

class RegistrationForm(forms.Form):
    hall_ticket_number = forms.CharField(required = False)
    name = forms.CharField(required=True)
    religion = forms.CharField(required = False)
    present_contact = ContactForm()
    gender  = forms.ChoiceField( choices = ( ('M', 'Male'), ('F', 'Female')),required = True)
    organization_contact = ContactForm()
    fee_details = FeeForm()

    def clean_hall_ticket_number(self):
        hall = self.cleaned_data['hall_ticket_number']
        if hall == '':
            self._errors["hall_ticket_number"] = ["Hall Ticket Number is NOt Present"]

        return hall 

    def clean_fee_detaills(self):
        amount = self.cleaned_data['amount']
        if amount == "":
            self._errors["hall_ticket_number"] = ["Hall Ticket Number is NOt Present"]
            self._errors["amount"] = ["Hall Ticket Number is NOt Present"]

        return amount 



       '''def clean(self):
        clean_data=super(RegistrationForm, self).clean()
        amount = self.cleaned_data['amount']
        if amount == "":
            self._errors["amount"] = ["Please Enter Amount"]
        return amount 
'''

Views.py

initial_values = {
    'name' : student.name,
    'hall_ticket_number' : student.hall_ticket_no,
    'gender' : student.sex,
    'religion' : student.religion,

    'present_contact' : {
        'address' : student.present_contact.address,
        'phone' : student.present_contact.phone_no,
        'email' : student.present_contact.email,
    },

    'organization_contact' : {
        'address' : student.original_contact.address,
        'phone' : student.original_contact.phone_no,
        'email' : student.original_contact.email,
    },

}
registration_status = False
if request.method == 'POST':
    form  = RegistrationForm(request.POST)
    #Checking Form is Valid or not
    if form.is_valid():
        text = register(request,student_id) # Processing of Register Page in registartion_contrib
        return redirect('/registration/{student_id}/register'.format(**locals()))
else:
    registrations = Registration.objects.filter(student = student)
    f_initial_values = None
    # Checking Registration Status 
    if len(registrations) > 0:
        registration = registrations[0]
        if registration.status == 'Done':
            registration_status = True
    # Feedetails of Student 
            feedetails = FeeDetail.objects.filter(student = student)
    if len(feedetails) > 0:
        feedetail = feedetails[0] 
    # Initializing the FeeDetails for Form 
        f_initial_values = {}
        f_initial_values['name_of_bank'] = feedetail.name_of_bank 
        f_initial_values['dd_number'] = feedetail.dd_number
        f_initial_values['amount'] = feedetail.amount 
        f_initial_values['date'] =feedetail.fee_date.strftime("%Y-%m-%d")   
    # Specifing the initial values for Forms    
    form = RegistrationForm(initial = initial_values, )
    if f_initial_values != None:
        form.fee_details = FeeForm(initial = f_initial_values)

     # Initializing Contact Forms PRESENT, Organization, Supervisor and Co Supervisor
    form.present_contact = ContactForm(initial = initial_values['present_contact'], prefix="present_contact")
form.organization_contact = ContactForm(initial = initial_values['organization_contact'], prefix="organization_contact")
form.supervisor_contact = ContactForm( initial = {
            "address" : student.guide.contact.address,
            "phone" : student.guide.contact.phone_no,
            "email" : student.guide.contact.email,
        }, prefix = "supervisor_contact" )
form.co_supervisor_contact = ContactForm( initial = {
            "address" : student.co_guide.contact.address,
            "phone" : student.co_guide.contact.phone_no,
            "email" : student.co_guide.contact.email,
        }, prefix = "co_supervisor_contact" )


return render(request, 'registration/register.html', {'student' : student, 'form' : form, 'registration_status' : registration_status,'registration':registration })

template.html

         Forms fields are specified as follows
            {{ form.hall_ticket_number|materializecss}}
            {{ form.name|materializecss}}
            {{ form.religion|materializecss}}
            {{ form.gender|materializecss}}

            {{ form.orgnization_contact.address}}
            {{ form.orgnization_contact.phone}}
            {{ form.orgnization_contact.email}}

            {{ form.present_contact.address}}
            {{ form.present_contact.phone}}
            {{ form.present_contact.email}}



          <div class="col s12 m12 l12">
                {{ form.fee_details.name_of_bank|materializecss  }}
                    </div>          
          <div class="col s12 m12 l12">
                    {{ form.fee_details.dd_number.errors }}

                {{ form.fee_details.dd_number|materializecss }}
                </div> 
          <div class="col s12 m12 l12">
                    {{ form.fee_details.date.errors }}

                {{ form.fee_details.date|materializecss}}
                </div>                  
          <div class="col s12 m12 l12">
                    {{ form.errors }}


              <br>{{ form.fee_details.amount|materializecss  }}
                </div>                  
            </div>