Stable Firmware for F5

kkuzhal 

Hello here is the link for what your device can support.  

The F5 hardware/software compatibility matrix

as for the Current Stable release using the n-1, the only recommendation that I can give you is to make sure it is either 16.1.x or 17.1.x as those are the supported versions for your upgrade. This link with show you this information.

BIG-IP software support policy (f5.com)