These few months have been pretty tough for all internet consumers on mobile phones. Since the lockdown in India began in the month of March, Youtube also lowered down the streaming quality to 480p resolution. This happened just after several major streaming platforms lowered the quality amidst the lockdown.
Once again you can enjoy HD content on YouTube, if and only if you are on a high-speed WiFi connection. If you phone even support 2K and 4K you can get all the options in the Quality section of YouTube App.
However, if you are on the LTE network, then you have to remain the same as of now. That means you will have a total with 480p quality as of now.
Source: Android Police