IBPS gives exact upload specifications in the official notification — follow those, not third-party guides.
The form asks for a recent photograph, signature, left thumb impression and a handwritten declaration.
Each upload has its own file size, dimension and format limits given in the notification.
Prepare clean scans in the correct format before you start filling the form.
If an upload is rejected, the form cannot be submitted, so do not use old or unclear scans.