On an Autoresponder email can I have an attachment?

If you were referring to the Submission PDF attachment that is included in Notification E-mail 

the Autoresponder E-mail does not have that option.

There is a workaround to this though -- that is make the Notifier behave like it is an Autoresponder email.

You can do this using conditioned email notifier. Check the user guide below

How-to-Send-Email-Based-on-Selection

Example condition :

in the example above, if Condition is satisfied, the Notifier will be sent to the email address provided by the user in the Email Address field.

Hope this help. Let us know if you need further assistance.

Addition:

If you were referring instead to attachments within the message body of the email -- it is not possible. You can only use a link instead of the file wherein the user can use the link to download the attached file.

If you include an Upload field on your form, the link to the uploaded file will be available also as a link in the email message.

We are pleased to inform you that it is now also possible to send uploaded file attachments within email notifications.

However, at the moment this is not yet possible within autoresponders but is in consideration.

You can read more about it here https://www.jotform.com/blog/223-New-Feature-Get-Uploaded-Files-as-Email-Attachments.