I have an ipad Air model number MD786LL/B what is the most up to date software version i can have?

Hello~ That is an iPad Air 1st generation an it can’t be updated any further than iOS 12.5.7. If you need a higher version of iOS you’ll need a newer iPad.

~Katana-San~

That is a nearly a 10-year old iPad model.

iOS 12.5.7 is the current OS version for this iPad model.

Hello ~ You are welcome and if you decide to get a second hand device read this by clicking on below to make an informed decision…

The All Too Common SAD Reality of Buying … - Apple Community

If shopping for a new one…

Apple Store - Official Site

Take care.

~Katana-San~