Firstly, both sides have a "no first use" policy. So we can go to war without worrying about the nuclear question.
Secondly, even one single Chinese nuke (3-4 megatons each), has more destructive power than India's entire nuclear arsenal (1 megaton in TOTAL).
India's own Armed Forces have officially spoken out, and said that "India cannot hope to match China by conventional OR non-conventional means".
Hell, they can't even supply their own Army with 2 days worth of ammunition.
The World is not what it was half a century ago. Secondly do you really think that if a push comes to shove that the nukes won't be used. Plus if India is attacked do you really think the world powers would sit idly a let things go on. The US has issues with China, do you think they will just simply let it go???