OLD IPAD SOFTWARE UPDATES

If you currently have iOS 6.x installed, given your description, you very likely have an iPad4. This iPad can be updated to iOS 10.3.4, this being the final supported version for this iPad.

Given the gap between the installed version and the available version, an over-the-air (OTA) update is not likely to be possible. As such, you will need to connect your iPad to a PC (with the current version of iTunes installed) or a Mac (with Finder) to update your iPad to iOS 10.3.4.

https://support.apple.com/en-gb/guide/itunes/itns3235/windows

What is the model number of your iPad.

If purchased in 2013, it could be either in iPad 4th generation or, perhaps, the 1st gen iPad Air, iPad Mini 2.

What model number is your iPad?

The “A” number is on the back of your iPad under the large printed “iPad”

And the model number can be found in the Settings app, General settings panel > About...

Hello,

What is your iPad’s exact model number?

Settings > General > About