Revs and shift points PLEEEEEEEEEEZE!
Your car has a tachometer in it for a reason. Essentially the tachometer is an engine speed indicator. On your tach, you will find a point where the numbers and grid turn red. This is understandably known as the red line which indicates the engine speed which should not be exceeded in any gear. The engineers who designed your engine KNOW what speed your engine is safe to run at (as opposed to self-appointed experts who THINK they know "by feel").
That having been said, your engine can safely be run at speeds up to the red line. Understand that the higher the engine speed, the more accelerated the wear on the internal components of said engine.
Hope this helps.