You will not have the horse power that you have at sea level. 10,000ft (3,000m)you will have about 67% of your HP, 15,000ft (4,500m) about 55% of your HP.
Octane, the higher you go the less octane you need. With the U.S. octane at see level I use 91 oct or 89 oct as I go higher 3,000ft (1,000m) I can use 87. In Cororado around the high passes 12,000ft (3,600) I can use 85 oct.
The way octane is measured is not the same in the U.S.
You will be running rich, the easiest way to lean the carb out is to put in a smaller main jet. It only takes a couple of minutes.
The bike will not run good at low RPM but it will get better as your RPM rises.
Be sure to put your stock jets back in when you go down in altitude.