Thanks @Rajkumar bro. I was in 3 month plan ending 11th Feb. I think 3 months is NOT a subscription and so no option to cancel it. But there was one option for "TOP UP" and I have selected this one year plan. Now my YT Premium validity is increased to 11-Feb-2023.
I use the PIP mode very extensively, to watch YouTube while playing games and doing other things.
I also use Background Play feature for listening to Podcasts, News and other stuffs.
Also, YouTube Music is my primary music streaming service. If I didn't use YouTube Music, I would've paid ₹999/Year for Apple Music or ₹1,189/Year for Spotify anyways. But here at ₹1,159/Year I am getting YT Premium as well as YT Music Premium.
Also, the number of Ads Free YouTube shows these days is simply infuriating.