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I am not sure if I have understood your question correctly. Do you mean to say that you want to specify what kind of file type users can upload?
Yes it is possible to allow the type of file in file upload field by adding file extension that users will be able to upload. https://www.jotform.com/help/29-Which-file-types-are-allowed-for-the-upload-field
" I.e say the form has to xxx details in it and only then they would be able to upload it." - I would request you to please explain your requirement a bit more in detail with an example and we will surely help you.
We will wait for your response.