If North Korea can deter South Korea; and Pakistan can deter India, and the threat of a third-party (US) can help Taiwan deter China, then India can deter China. We won't be facing the Chinese with muskets and hawaii chappal this time. We have a modern mechanized army that has dozens of imaging and military satellites in the sky. Credible minimum nuclear deterrence is still a thing. Nuclear ambiguity is keeping the US from touching countries like Iran. Why? Because if it turns out that Iran has nukes, it will lob them at the American staging areas, killing thousands of troops and burning billions worth equipment to the ground. If the Chinese have occupied Indian territory, there is nothing stopping an Indian nuclear strike against the Chinese in that particular piece of land (which is Indian). We wouldn't be nuking China, but Indian territory under Chinese occupation.
Unlike North Korea or Iran, India has a nuclear triad: both fission and fusion weapons, anti-satellite weapons, MRBMs, air-launched cruise missiles, and nuclear submarines with SLBMs. Not even the Americans would do something as stupid as invading a country with an active N-triad. Assuming the INS Arighat secret-commmissioning+deployment rumor is true, we now have the ability to lob up to 24 nukes at cities like Shanghai, Beijing, Tianjin, etc., while leaving the Chinese very little BMD response time against a volley.
What's happening in Ladakh is a salami-slicing attempt that's been stopped dead in its tracks by an Indian counter-mobilization. They're still throwing rocks and slurs at each other. Eleven Jaundice needs to show his wang to the National Congress in Beijing, and creating a war-like situation along multiple frontiers is a nice way to silence opposition within CCP, because his ass was on the line after corona.