You lost the war because the stupidity of your leadership as reflected in the following points:
1) Your leadership foolishly believed by forwarding into Chinese territory (as perceived by the Chinese because they don't give a sh!t of colonial McMahon line), by helping Tibetan riots, the Chinese would keep signing Hindi-chini bhai bhai instead of hitting back. Be rational: once getting invaded, nobody would behave as such.
2) When the Chinese did give you a shock by hitting back on you, your foolish leadership, instead of relying on experienced military leaders, they still relied on nepotism. Nehru made Kaul, his relative, the army chief who never saw a Chinese soldier before.
In retrospect, just asking yourselves: do you know the Chinese well today? Is nepotism/family dynasty an essential part of your culture today? Is you main job flattering your managers today?
If you answer is yes to 1 or 2 of the above 3 questions, forget about retaliating on China. If your answer is yes 3 out of 3, which most probably would be as of today, you better wait for 5-10 generations while you are improving.