The question you asked it entirely too vague to properly answer! Nobody here will be able to give you the information you require without knowing what car you have, what engine you have in said car and what modifications you have done to said engine, specifically the valvetrain.
Some motors are built to handle 6500 RPM while others are built to handle 10,000 RPM. It all depends on your set-up. However, banging a motor off or near the rev limiter all the time WILL shorten the life of the engine! It may still last a long time if it is built right but everything has a breaking point, especially when you push it to or near it's peak stress point all the time.
Engine? Cams? Springs/Retainers? ECU? How many miles on it? Compression and genereal overall health of the motor?? Lots of variables to consider. There are a lot of knowledgeable guys on this forum, so if you give them the details of your set-up they will steer you in the right direction.