It sounds like it is geared for approx 200 km/h indicated top speed at redline. (5000 rpm at 100 km/h, and 10,000 rpm redline.) That sounds a bit low for a 750cc bike. It is possible that someone has put a smaller front sprocket or larger rear sprocket on it.
If you want to change it, find out how many teeth the front sprocket has and check that there is clearance around the sprocket, and if there is room, put on a sprocket that is one tooth bigger. That should give you approx 4700 rpm per 100 km/h (and about 215 km/h indicated top speed at redline). That sounds about right for an engine of that size. You could even go further (if there is enough clearance around the sprocket to allow it, and if there is enough room for the axle to be brought forward), or you could fine-tune it with a rear sprocket a couple teeth smaller. It will pull the taller gearing no problem.
My FZR400 has taller gearing than stock and it does 6000 rpm at indicated 100 km/h. (Stock was around 6500.) cbr125 does 7700 rpm at indicated 100 km/h.
