Thank you, 3dcopy worked for the volumetric data but not for the grayordinate timeseries.
It gives following errors:
3dcopy rfMRI_REST2_RL_Atlas_hp2000_clean.dtseries.nii test1
++ 3dcopy: AFNI version=AFNI_2011_12_21_1014 (Jan 8 2014) [64-bit]
*+ WARNING: missing view dataset: rfMRI_REST2_RL_Atlas_hp2000_clean.dtseries.nii+orig - SKIPPING
*+ WARNING: missing view dataset: rfMRI_REST2_RL_Atlas_hp2000_clean.dtseries.nii+acpc - SKIPPING
*+ WARNING: missing view dataset: rfMRI_REST2_RL_Atlas_hp2000_clean.dtseries.nii+tlrc - SKIPPING
** FATAL ERROR: no datasets found!
** Program compile date = Jan 8 2014
nifti_tool -disp_hdr rfMRI_REST1_LR_Atlas_hp2000_clean.dtseries.nii
** unknown option: 'rfMRI_REST1_LR_Atlas_hp2000_clean.dtseries.nii'
(I run again in the same directory as the data, and tried on different subjects.)