I hope India regulates entities like Byjus. Every government should have khan-academy like videos made by the best teachers available to all citizens for free.
Check out NPTEL - it's Khan Academy, but by the government. Don't know about other streams, but for Engineering, it has IIT Professors teaching the lectures.
I have seen some Byju's math videos on YouTube. Honestly, they are fairly good quality and the teachers seem to be quite engaging. Of course, they are not complete courses - for that you probably need to sign up for Byju's.