yeah its from my observation in that google tracking spreadsheet. Applications from India are sent to NDVO as well as Ottawa. I am not sure how they determine where to send the application.
from what I read in the IRCC website, they say , it all depends on the work load in the respective Visa Offices and they decide where to transfer the application to.
2021 Spousal/Common Law Tracking Tool - Google Sheets
while most applications from India are sent to NDVO , some are sent to OTTAWA as well. The ones in Ottawa office seems to be processed quicker.