Under certain circumstances, an iPhone or iPad user can restore or upgrade your version of iOS for a higher or lower. Apple should be signing the version you want to restore to do the action. In this case, you can not upgrade, restore or to downgrade to version 9.3.1 because Apple has stopped signing the aforementioned version
The fact is that Apple takes such measures to force users to have the latest version available also to stop signing certain versions, requires the community Jailbreak update the version to block the Jailbreak in the most current version.
In the case of jailbreak, it is only known that the tool was launched last compatible with iOS 9.1, in fact, very few users are left in version because they were expected to launch a tool compatible with higher versions.
If you're using iOS 9.1 or below, you can do the jailbreak with the necessary tool according to the version of the device, however, Pangu / TAIG have not said whether or not they are working to launch a compatible tool (but it is believed that if they worked On it).
Should be in iOS 9.3.1, my recommendation is to stay in this version and not update or iOS 9.3.2 (at least until it is known whether there will be or not jailbreak for this version).
If they're on iOS 9.3.2, we can not do much, since or we were in this version or update to the Beta version of iOS 9.3.3, however, my recommendation is to stay at 9.3.2 if it is the case.
It is known that Luca Todesco was able to make the jailbreak on iOS 9.3.2, however, his intentions have never been to launch any tool or as did say, however, this person has released the exploit used for any group that you take a tool to jailbreak moments that do not seem to come soon.
If you want to be sure the above, you you can check on THIS PAGE where they can download any version of iOS, however, note that the versions marked in red are not being signed by Apple, marked in green are being signed by Apple