Hi,

You can create a page for the admission purpose on the website and then upon clicking the submit button of the form,  you will get the entered values in the route of the corresponding page.

From this route, you can create a record in the backend.

Creating template:

<template id="support_submit_ticket" name="Submit Support Ticket" page="True">
    <form action="/support/ticket/process" method="POST" class="form-horizontal mt32" enctype="multipart/form-data">
        <div class="form-group">
            <div class="col-md-offset-3 col-sm-offset-4 col-sm-8 col-md-7">
                <button class="btn btn-primary btn-lg">Submit Ticket</button>
            </div>
        </div>
    </form>
</template>

Then upon clicking the submit button, you will get the entered values in the route: /support/ticket/process

@http.route('/support/ticket/process', type="http", auth="public", website=True, csrf=True)
def support_process_ticket(self, **kwargs):
    # in **kwargs you will get values from the form
    # using this you can create record in the backend
    values = {
       # set the values
    }
    request.env['model_name'].sudo().create(values)
    return werkzeug.utils.redirect("/support/ticket/thanks")

For more you can have a look at this module available in the odoo apps store :  https://www.odoo.com/apps/modules/10.0/website_support/

Thanks