What is difference between intramolecular redox and disproportionation redox
Disproportionation is a redox reaction where one element works both ways, with part of it being oxidized and another part reduced. It does not have to be intramolecular in the strict sense, since the oxidizing and reducing agents do not necessarily come from the same molecule (though they come from similar molecules, of course). Think of the well-known reaction:
$$\ce{3KClO -&gt; KClO3 + 2KCl}$$
It is certainly a disproportionation, but one may hardly call it intramolecular; there is not much going on within one molecule (or rather within one ion, for all of these are ionic compounds). Chlorine oxidizes chlorine; now, one ion contains one atom of chlorine, so to oxidize anything it needs to find another ion in the first place.

Intramolecular redox reaction occurs when we have the oxidizing and reducing agents within one molecule. They may or may not be of the same element. In the former case it is going to be a disproportionation, but not in the latter. Think of TNT:
$$\ce{2 C6H2(NO2)3CH3 → 3 N2 + 5 H2O + 7 CO + 7 C}$$
See what's going on? Basically, N oxidizes C. They are indeed from the same molecule, so this may be intramolecular, but they are not the same element, hence this is not a disproportionation.