Yeah, people here forget that USSR at one point was seriously considering nuking China. The problems between India and China are peanuts in comparision. India also has no serious business in interfering in Taiwan issue as that region doesn‘t belong to India‘s core interests. I would even say, India doesn‘t any sensitive geopolitical problems. Even the problem with Pakistan can be solved by letting India be. India and China are maturally suited for being allies. It‘s just some artificial problems kept the two st odds with each other for some reason.
They were not just considering nuking China, they actually threatened to do just that. Funny enough it was ironically US dissuasion which made them reconsider things. Additiinally you forget that the China/Russia border was one of the/if not the most militarized on earth at the time(some claim almost 2.5million troops at some point) and both countries even fought a war/clashed over the border as well. Some people tend to forget the level of enmity that existed between China and Russia(we humans forget very quicky. Lol ) not just over the border issue but even more so ideologically. So it was a deep enmity(Russia was China's number 1 enemy and threat then by far) unlike the superficial one between India and China which is just a legacy of british colonial rule and bad demarcation of the border which lingers to the modern era, compared this to the Chinese- Soviet Russia issue which stemed from something even deeper for China back then since it was the result of the unequal treaties imposed by Russia who took advantage(like they are did recently with Georgia, Crimea and now Ukraine and even in the past with Japan at the end of the war over sakhalin island when japan was basically already defeated by the US) of a weak china and seized and carved out vast territories from China(the land they carved out/seized is almost the size of western europe). So Chinese leaders would have found it hard to allow the border issue to be won and taken by soviet Russia again. So the enmity and differences was much more deeper, yet they still settled it peacefully eventually albeit it was also due to the US/West weakening Soviet Russia and leading to the fall and bankruptcy of their empire , so they had to negotiate with China and agree to some concessions with China eventually. They never would have done so if the soviet union didnt lose their competition with the US. So ironically, China was one of the biggest winner of Soviet collapse. Lol
So i believe China and India should and wohld eventually find an agreement on the border dispute. Its in both intersts to do so to be honest. I know pride makes it harder but they should act like big matured powers and come to an agreement(maybe juat recognise the land each hold at the moment as each other territory and then agree to demarcate all the border while making some concessioms on each side). They cant keep the dispute status quo forever, plus its mostly just some mountain of barren rocks anyway. Lol