Hi Aleem,
I haven’t had much experience with Blender to UE but that does look like you purchased a rigify riged model.
It might be possible to edit the metarig and then regenerate – however Blender bones always have the y axis pointing down the length of the bone so this might not solve your issue.
If this is a rigify rig you might benefit from using something like the GameRig add-on (or similar) from CGDive.
Basically it will convert your rigify rig into a game engine friendly version with a couple clicks. I have not used this but Todor (CGDive) has a couple tutorials on what you need to do to Blender rigs to get them into the different game engines. (because as you know all softwares have different requirements and orientations etc). But the add-on automates all of this.
This is his site https://cgdive.com/
But also check his Youtube because that is where the Blender to Game Engine series is located (I don’t think he has that one on his site??)
