IMO Bruce Wayne has three options:
Option 1
1 to 8
Bruce Wayne takes a dive
If he's not K.O. he uses breath control and simple meditation to satisfy everyone he is K.O.
Option Two
1 to 8
Bruce Wayne Tanks
He'll throw his mind into a delta state, His body will be completely relaxed (He won't be standing straight up with his feet planted flat) When they strike - they'll be throwing him from the transitive delta state into full alpha wave wide awake state.
Have you ever seen (or heard) what happens
when some one wakes up through some shock / collision / contact with another person while sleep-walking?
Well thats the state Bruce Wayne will put himself in - given this to work with:
Using rigorous scientific analysis,
Must not actively fight
Must only try to stay conscious after each free shot.
Simple Meditation For Bruce Wayne
Bruce Wayne has a Third Option
Talk them down
They are hitting an unarmed non threatening civilian they do not have a reason to be hitting.
Bruce Wayne is not limited to speaking he can smile + communicate a warm and genuinely friendly greeting (you can forget about him being afraid)
If he engages them verbally with genuine human emotion 1 2 4 5 6 8 have no business hitting him.
7 Bruce Wayne would lead with this: "How Much Are You Being Paid For This?"
3 will strike him - probably - and will probably stick around to kiss it better.
3 x 8
Bruce Wayne is Intelligent
Against some opponents he is likely to make (simultaneous) use of two or more available options, which are:
Take A Dive / Take A Knee
Tanking
Engage The Mind - Punches don't hit Bruce Wayne - People do.