Indian government has been pushing Aadhaar in every sense by lying and coercion methods, even when Supreme Court of India has clearly mentioned that Aadhaar is absolutely optional.
The truth is that Aadhaar is absolutely optional for all purposes and services in India. This applies to both government and public services and none can demand Aadhaar for these services or purposes.
Any person or organisation demanding Aadhaar is in contempt of court and you can sue him/her/it.
(1) Aadhaar Refusal Form,
Source: Aadhaar Law.