I can’t link my debit card to my Apple Music

See -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

See also -> About billing for Apple subscriptions and media products in India

About billing for Apple subscriptions and media products in India - Apple Support

India

•           Apple ID balance (from adding funds)

•           Net Banking (adding funds only)

•           UPI (adding funds only)

You can use / pay with your Apple ID balance, ->  Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)