For others, please follow through what this forum admin/folks has suggested. However, Singh and Kaur is so common that it automatically gets placed inside of surname field. Changing that in India on surname [passport] is huge hassle. For us, we always checked after each step to make sure its getting processed correctly. We did not change any documents in India. When in doubt just tell the officer to put Singh/Kaur in the surname.
Hello,
For my wife visa everything worked out when we placed Kaur in the surname field. Anytime you fill out any application related to US [visa, NVC, social security, citizenship] keep putting Kaur in the surname field. It will be fine.