Specific iOS install required....help

[Pacemaker1000]

hi all. I have a app giving me problems on the iPad 3 running 9.3.5 and also on iPad Air and iPhones running 10.2. Also have an iPad mini run iOS 7 but the app need iOS 9 minimum.
So looks like downgrading is out but can I jailbreak the iOS 7 iPad then install an iOS of my choice by downloading one?

Thansk

 

[Applejuiced]

No.
Jailbreaking doesn't let you install any IOS of your choice.