Observe Russia's strategy. They did not go for blitzkrieg. They went in a measured approach since they had anticipated support from fellow Slavic people and hoped to install a puppet regime.
China on the other hand will not have such problems. So in terms of strictly Conventional war, India will lose with China head to head. At the same time, I don't think China can hold on to Indian territory for long time either. That's a lot of hostile people to subdue and control. So eventually they will also have to withdraw.
In terms of Bangladesh, I don't think any Bangladeshi ever claims we can take on India in a conventional war. It will be the same war of attrition through guerilla tactics and any Indian invading force will eventually have to withdraw in long term. India doesn't have the power to invade and control a hostile population of 150+ million.
That said, referring back to the topic, that guy is clearly a joker to think India alone can win against China, where US wouldn't dare it.