I have an admin rights but still I am not able to download underlying data. "File Format" option getting disabled while selecting Underlying Data option and getting blank excel/csv file.
please help to get of this problem.

I have an admin rights but still I am not able to download underlying data. "File Format" option getting disabled while selecting Underlying Data option and getting blank excel/csv file.
please help to get of this problem.

I can see two options:
The dataset is situated in another Workspace where you don't have adm rights.
Your dataset is in the same Workspace as the report. In this case, you have to enable build permissions on the dataset.
More info on building permissions: https://www.fourmoo.com/2019/10/08/power-bi-bulk-changing-permissions-read-reshare-build-on-datasets/