What was found
AFTER TAKEOFF CLEARANCE WAS RECEIVED PILOT REQUESTED THRUST/N1 TO BE SET. AT APPROXIMATELY 35 KIAS THE CREW RECEIVED THE R GEN OFF AND BOTH AUX BUS EICAS MESSAGES. THE TAKE OFF WAS REJECTED AND THEY CLEARED THE RUNWAY. QRH CHECKLISTS WERE COMPLETED ALONG WITH FLOW CHART AND BRAKE COOLING ASSESSMENT. THE FOO/MAINT CON WERE CONTACTED AND THE PILOT ADVISED THEY WOULD TAKEOFF AFTER THE REQUIRED BRAKE COOLING PERIOD EXPIRED. A/C RETURNED TO SERVICE. MTC DEFERRED THE RT ENG GEN PRECAUTIONARY PER MEL 24-00-1-1 AFTER ARRIVING AT SCHEDULED AIRPORT. A/C CONTINUED IN SERVICE.