Honestly, a lot of the documentary is a mixture of interviews and CCTV camera footage with a fairly even handed narrative on the top – it, by itself, isn't that shocking and certainly isn't presented in a particularly sensationalist way. I'm amazed by the reaction it has generated. Yes, there's some post-colonial history there and it doesn't look great that it's the BBC that has made it, as opposed to, say, a US or continental European broadcaster. Still, nevertheless, when you see videos of policemen beating up (usually female) students with canes because they've had the audacity to protest, it can't help but make you think.
If you're interested, you can get it (legally) in the UK here: [1] and searching for "India: the Modi question" will most likely provide it elsewhere.
[1] https://www.bbc.co.uk/iplayer/episode/p0dkb144/india-the-mod...