how to download ios10 on ipad and where to find it

I surmise that you have either an iPad2, iPad3 or first generation iPad mini. These devices can only be updated to iOS 9.3.5 (WiFi Only models) or iOS 9.3.6 (WiFi & Cellular models).

Apple ended update support for models in September 2016. They cannot be updated to iOS 10 or later major versions of iOS, as the internal hardware does not meet the minimum technical requirements for new versions of iOS/iPadOS. This limitation cannot be bypassed; these older models are all 32-bit architecture devices, whilst all recent versions of iOS/iPadOS are designed for 64-bit hardware platforms. The iPad2, iPad3 and iPad mini1 are effectively obsolete.

You may wish to consider that compatible Apps for older models of iPad are increasingly difficult to find - as third-party developers are increasingly dropping support for older versions of iOS preceding iOS11/12/13. As older versions of Apps are removed from the Apple App Store, you’ll not be able to (re)download or install them - which may severely limit the usefulness and utility of your iPad if you should you ever need reset or restore your iPad. As such, if you want or need to access most current Apps, requiring more recent versions of iOS, you’ll need to consider replacement of your iPad with a newer or current model.

Of current models, even the entry-level iPad7/8 has specifications and capabilities that massively outperform you current iPad - and is compatible with the vast majority of current Apps. Other models are more powerful still.

I hope this information provides helpful and succinct clarity as to your available options - and the limitations of your current iPad.

All iPhones and iPads models can be updated only to the latest (most recent) iOS/iPadOS supported version.

That said, depending on your device model, see this list for iOS/iPadOS compatibility:--> https://everyi.com/by-capability/maximum-supported-ios-version-for-ipod-iphone-ipad.html

Regards

Giulio

If your iPad is still on iOS 9.3.5 or 9.3.6, then your iPad is too old / too outdated. It cannot be upgraded further. iOS 10 was released in September 2016 and is also outdated, the current version is iOS / iPadOS 14.

You are better off by buying a new, current-gen iPad. iPads stuck on iOS 9 are atleast 8 years old and older. Such an obsolete device just cannot run newer versions.