Hello @Lite_Yagami welcome to community forums!
As far as i know we could use Debit cards for payments too. Infact i had used one myself for premium susbcription.
Sometimes rupay card isn’t accepted so you have to check for yourself , but a visa or mastercard debit card should surely work.
I think for enabling recurring payments an e-mandate would have to be created.
Other payment methods like UPI would definitely be much more convenient for us but i don’t think it will be realised any time soon as it will increase the handling and transaction/compliance cost for bitwarden with relatively less user base.
Since , users from each country may find some other payment methods more convenient to them , maybe google play gift card method could be considered in future as google usually has support for local payment methods including UPI.
Feature request for it is here Allow payment with google play credit
But again i guess google would be charging some percantage based fee for it , so it may not be easy for them to go for this option too 
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Cheers 