tkmedit subjectname rawavg.mgz is the way to visualise the volume. The first image. This is what happened.
s0964091@CRIC-0012:~/Desktop/Allimages/MRIscan/janani/CRIC-0014_5679.adb.DICOM$ tkmedit subj001 rawavg.mgz ERROR: cannot find /home/s0964091/Desktop/Allimages/MRIscan/janani/CRIC-0014_5679.adb.DICOM/jan/subj001/mri/rawavg.mgz
Error: Loading volume rawavg.mgz
Couldn't read the anatomical volume.
Tkmedit couldn't read the volume you specified. This could be because the image format wasn't recognized, or it couldn't find the proper header, or the file(s) were unreadable, or it was the wrong size.