I guess this is most common issue for most of the Indians. It is similar to my case. Usually in our birth certificates "place of birth" will be listed with hospital name/taluk/mandal/colony name/town/etc. However, usually in the passports the "Place of Birth" is listed with District names. So, if you have the birth certificate then it should have something like "Government of Tamil Nadu" and "Chennai Municipal Corporation" and your place of birth will be listed as mentioned above i.e. hospital name/taluk/mandal/colony name/town/etc. Now, if you check your passport the place of birth should be listed as "Chennai."Technically, this should resolve this issue. Not sure if we require one more affidavit as my friends who has the same issue got their GC's without getting an affidavit. Not even sure what affidavit we should get. Experts, please correct if I am assuming wrong.