The Chennai regional office wont be able to help as they only deal with renewals and not initial issue
You can file an RTI online here with the Ministry of Civil Aviation.
https://rtionline.gov.in/
They will forward it to the DGCA . If you see an option for DGCA then of course choose DGCA
Please write a nice clear letter asking your questions very clearly. If you write a vague or unclear letter their response will be more or less the same.
They will send a reply by post within 1-2 months