Can i get the Jot Form app on any device (Android)

And if so, are there any minimum requirements for the tablet

Also , how much mobile data does the average form use, were trying to work out how much data the SIM cards need per month

JotForm can be used on most major devices to both build and manage your forms.  Any modern tablet should be able to run the form builder without issue.  Data usage would vary greatly depending on the need to upload files, add images to the form, anything of that nature.  I would test on your end with an active device with what would be your normal usage.  Monitor that usage and then estimate from there.