Ver 10.3 is the os am unable to install any update

Yup.

If your iPad model has been stuck on iOS 10 for all of these past years, then you own an over 8-year old, 2012 iPad 4th generation.

That iPad model cannot ever upgrade beyond iOS 10.3.3/10.3.4.

Your over 8-year old, iPad 4th gen model is too old, now.

Apple ended support for 8-10 year old iPads, at least, over 3 years, ago.

The internal hardware in that iPad is too old, too underpowred and completely incompatible with all later versions of iOS/iPadOS.

Virtually, all third party iOS app developers ended/stopped/abandoned supporting these old iPads over two years, ago.

There are virtually, NO MORE older iOS 9 or 10 compatible apps available from the Apple iOS App Store, any longer.

Simply put, your 4th gen iPad is too old and obsolete now.

Sorry.

If you need/want an iPad with an up to date iPadOS with access to current, updated apps, then you really need to seriously consider a new iPad model OR a much “newer” , used iPad model capable of running the latest iPadOS versions.

There are plenty of newer, older iPad models that can run the latest, current versions of iPadOS.

Sorry & Best of Luck to You!

Update to iOS11 or later isn’t possible.

If your iPad is currently running, or cannot be updated beyond iOS 10.3.3/4, then have an iPad4.

Update support for iPad4 ended September 2017. The final iOS releases for this model were iOS 10.3.3 (WiFi Only models) and iOS 10.3.4 (WiFi & Cellular). iPad4 cannot be updated to any later major version of iOS as it lacks the minimum hardware requirements needed to run more recent versions. The 32-bit platform upon which the iPad4 is based is effectively obsolete.

Many App Developers have also dropped support for older devices and iOS versions preceding iOS11/12/13 - and have withdrawn older versions of their Apps from the Apple App Store. Withdrawal of Apps supporting older models of iPad is making their utility and usefulness significantly more limited. Once compatible versions Apps are withdrawn, you’ll not be able (re)download or (re)install them.

If Apps that you need to use now have higher minimum iOS-version requirements, your only option is to replace your iPad with newer model. Of current models, even the entry-level iPad8 supports current iPadOS 14 - and has hardware specifications and capabilities that vastly outperform your old iPad4.

I hope this information is helpful - if only in clearly stating the limitations of your iPad4 and your available options.

Most likely your iPad model (perhaps an iPad 4th generation) cannot support iOS versions beyond the one that's currently running on it, because of hardware incompatibility.

Regards

Giulio