Hi Abir,
I hope what will be written here do the job for you!!
Here is the same topic that has been answered by @rsmith, https://community.mrtrix.org/t/calculating-the-tract-volume/3936?u=salah.
In terms of the 3D visualization:
You can see the 3D volume of the bundle in mrview > view> Volume render. Then you need to go to Tool > View options > In the section [clip planes], there is + with a little arrow, and when you press it a sublist will appear that has axial, sagittal, and coronal. Choose the plane and you will see the 3D of the bundle.