A couple of examples for this would be that in 2011 Congress filed sedition cases against 3500 farmers for protesting against the construction of a nuclear power plant in Tamil Nadu.
Kundankulam nuclear power plant? That is Jayalalitha's government. AIDMK was technically a soft Hindutva party if there's such a thing in Tamil Nadu politics. Misuse of sedition law? Yeah, if there's anything that's Indian culture then it's having ambiguous and broad laws to target people whimsically. In fact, the current BJP government does it more and has been creating more draconian laws.
What you could actually criticise Congress is for putting people like Aseem Trivedi behind the bars during the Anna Hazare movement. But the same thing happens now and perhaps worse.
Speaking of Hazare, there was a recent video of him criticising Kejriwal which ANI tweeted and he's listening to whispers and repeating. When you need this guy for propaganda against the current opposition, he's always eating and healthy.
but for some reason which is beyond me the opposition don’t seem to do so.
ohh, opposition is doing their best but the media is very partisan now. Openly dehumanises people - something which was never the case in India. That's exactly what people are worried. Of course, then there is a set of half-educated 'uncles' who think "opposition is not doing anything".