Yes, Nokia 1 have the removable battery.
Yes, Nokia 1 does have the support for 18 Indian languages. You can change the system language from the English to Punjabi easily.
Yes, Nokia 1 does have the FM radio.
Yes, Nokia 1 does support the Tamil language.
The Nokia 1 is an inexpensive Android smartphone, and as you can tell from the Nokia 1 review, you very much get what you pay for.