Here you will find existing number ranges

https://3.bp.blogspot.com/_ZYzSVDOY_...CWM/s400/5.JPG

To create new range

https://1.bp.blogspot.com/_ZYzSVDOY_...Kw0/s400/6.JPG

Look at the Number range of our company is 6000 - 69999

Which is mentioned at C1 (C1 need to assign to our company)

If your client wants one range for one branch and one range for other branch so you need to maintain two different rages like

C1 : 06000 - 69999
C2 : 70000 - 99999

And Assign C1 to your one branch (Personnel Area) and C2 to other personnel area.

You can also to your employee Groups/Sub-groups or Company code...according to your BP.

https://4.bp.blogspot.com/_ZYzSVDOY_...M0c/s400/7.JPG

And look at the Current Number is 0

And also look at the BOX saying EXTERNAL NUMBER RANGE, if you want user give manually number range TICK THIS OPTION if you don't want user to give let SAP give automatically so don't Tick.

https://2.bp.blogspot.com/_ZYzSVDOY_...9fE/s400/8.JPG

Press to save

https://4.bp.blogspot.com/_ZYzSVDOY_...FuA/s400/9.JPG