I will tell what worked for me,in my RPi3:
Through putty run the following script (specific for RPi3):
wget
https://raw.githubusercontent.com/crcerror/OpenBOR-63xx-RetroPie-openbeta/master/scriptmodules/openbor-6xxx-RPi3/openbor-v6510-RPi3.sh -O- | tr -d '\r' > /home/pi/RetroPie-Setup/scriptmodules/ports/openbor-v6510-RPi3.sh
This will install a script in retropie setup, and show OpenBOR 6510 in experimental packages.
Go to the experimental packages and install OpenBOR 6510.
After that you will need to create a cfg fil. So still in putty, type the following:
sudo nano /home/pi/.attract/emulators/OpenBOR.cfg
press enter
Then copy the following text (to paste in putty just press right click in the mouse):
# Generated by Attract-Mode v2.6.1
#
executable /opt/retropie/ports/openbor-v6510-RPi3/./OpenBOR
args "[romfilename]"
rompath /home/pi/RetroPie/roms/openbor/
romext .pak;.PAK
system OpenBOR
artwork boxart /home/pi/RetroPie/roms/openbor/boxart
artwork cartart /home/pi/RetroPie/roms/openbor/cartart
artwork flyer /home/pi/RetroPie/roms/openbor/flyer
artwork marquee /home/pi/RetroPie/roms/openbor/marquee
artwork snap /home/pi/RetroPie/roms/openbor/snap
artwork wheel /home/pi/RetroPie/roms/openbor/wheel
Save and exit
You can set different locations, just edit the text above.
Then place the pak files (do not extract then) in the designated folder (in my case /roms/openbor), place the art in the respective folders.
Go to attract mode, press tab, or the button to enter the menu, go to emulators, select OpenBOR, go all the way down and generate romlist.
Then go back to the menu, go to displays and set the theme and filters.
Thats it.