Thank you for your response. I note that your message didn't go to the
tz@iana.org mailing list. I've copied the list again with this message. I have no official status on the team that maintains TZDB; I'm merely an interested observer. Therefore, anything I say can be overridden by that team. But I believe I'm following the "party line" on the topic.
I'm not clear what your response is claiming. Are there 50 different sets of rules for different cities in India for changes in time zone since 1970? Unless there are different time zone rules for different areas of India, one entry does for all of India.
Whether I like it or not (and I don't), America/Los_Angeles is the official name for the time zone in all of California, even the bits that would rather Los Angeles didn't exist. To have the remotest chance of success, you will need to persuade those who maintain the TZDB that there are different time rules for different parts of India since 1970-01-01. You can look through the mailing list archives to see other people's request for similar changes that have been denied for similar reasons. Occam's Razor (
https://en.wikipedia.org/wiki/Occam%27s_razor) comes into effect: Entia Non Sunt Multiplicanda Praeter Necessitatum (Do not multiply entities unless necessary). Adding more city names would be multiplying entities without good reason.
If you wish to create historical information for different time zones in India before 1970-01-01, then you may have some luck, but you'd need to provide the data, with references to official or authoritative sources of information about the different time zones. But that becomes more specialized — it might not make it into the main TZDB distribution because the time zones within India have not diverged by location for the last 50 years or more.