For those who want to look into using your Alesis SR-16 as a slave drum Machine with the OB-6, I found a workaround... I'm basically MIDI daisy chaining as follows: OB-6 > Korg Monologue > SR-16
As such I'm able to sync the MIDI clock of the OB-6 as the master and the Monologue and SR-16 slaves.
The weird thing is that if I want to connect the SR-16 as a slave directly from the OB-6, the SR-16 ignores the Master Clock from the OB-6.
I guess for now this solves my issue, or better yet, the Korg Monologue solves my issue.