Follow the steps below to upload thumb impression in the application :

1) Take a white paper, dip your thumb in any ink preferably blue and  paste it over paper..By this you will be able to get your thumb impression on a paper ..

2) Scan that paper using any scanning app..

3) Go to application form page and click on browse than open that folder in which you have saved that pic.

4) select that pic and upload it ..

Let me know if you require any further information..

Good Luck!!