Hey @viku welcome to the community! 
Regarding the Tap and Pay functionality, we have this on the roadmap but we haven’t picked it up yet.
Do you have ideas on how this could be integrated into the app? Here’s a concept shared by @RSSM . Here - NFC-Payments through our phones
Question, is it available only for aggregator apps like Gpay, PhonePe, etc and not banks? Not sure if it’s available on the SBI app.
Regarding adding the Jupiter card on Gpay, it’s a known issue. We’re working on this 