B2 visa- DS 160 form - Location issues

[Truptipatil]

Hi,

I'm trying to get B2 visa done of my parents. They reside in Belgaum, Karnataka . While filling the DS 160 form we chose Mumbai as the intended location for interview, since the travel distance is less compared to Belgaum-Chennai. But while applying for the appointment we could only get Chennai since they are in Karnataka. The DS 160 is already submitted and we are not able to go back and change the location to Chennai . Can we use the same form or do we have to start a new application? We are yet to complete the interview appointment application and would like to know if there is still an option to go to Mumbai for interview instead of Chennai.  I read all mixed info about this online. Some say we need to start new DS 160 application. Some also say it is ok to go to any location we want to for interview and it need not be specific to residing state. Kindly help. We need to finish the process and get visa dates ASAP. 

Thank you in advance.

Trupti Patil