It sounds like you're looking for an interesting review that covers the "index" (possibly meaning the tracklist or song ranking) of Aashiqui 2, but with a 2021 top perspective — meaning a retrospective or updated take from 2021.
A melodic duet capturing the early stages of the characters' romance. Galliyan (Saiyaara)
Shot in a single, rain-soaked take. Aarohi’s raw audition transforms into a breakthrough. This scene alone convinced many that Shraddha Kapoor was a singer (she trained for months).
As of 2021 and beyond, you can watch Aashiqui 2 on:
Theme: A modern love story between a bodybuilder and a Zumba instructor that addresses transgender identity.