hello ambati,

if your thumb impression is rejected in NBE form, these could be the reason please go through the instruction and check out it.

1.check the background color, it should be white.

2. image should be clear, it should not be blur.

3. The file size should be according to the given format.

4.The file extension should be of proper format.For  example jpg. pdf.png etc.

If your file is not uploading after that then you contact the help line. here is the link https://www.cns.natboard.edu.in/CandRv1/CandR/index.php .

and also as they are asking for test center the reason could might be the verification of your application/ID.

I hope this will help you.

thank you!