Like Isaac said, the poor spelling and grammer make it rather difficult to understand what the situation is and what the real question is.
The desired length for the rope is going to depend on a lot of factors.
The faster you ride, the farther back you will likely want to be as the wake narrows with increasing speed.
The greater your "pop" (factors include size of the wake as well as skill of the rider) the farther back you may want to ride. If you can get the air, getting farther back will give you more to work with, increasing your hang time.
I doubt that anyone could tell you how far back you would want to be without knowing you and your boat personally.
My recommendation is to get a rope with multiple tie off points. It is common for wakeboarding ropes to come as a three section line, where the main line is 55 feet long, then a 10 foot section and a five foot seciont. Altogether the rope is 70 feet long, and with a handle that has 5 feet of rope on it you are at 75 feet.
The tie off points are generally made so that you can totally remove the section, leaving you with a little piece of rope either 5 feet or 10 feet long with loops at both ends. Some shops will sell these little lenghts of rope so you can just add them to your existing rope.
Tip: If you are like most of us and have managed to ruin a good rope by wrapping it in the prop, save the extensions!
If you have a few of these extensions then you can quickly adjust the length of the rope for each rider and boat.
I don't recommend attempting to splice a wakeboard rope unless you really know what you are doing. The old fashion ski line was easy, but the low stretch lines are a bit harder and it is a real bummer to have your line come apart when you are really pulling hard!