The answer is simple, once you realise that one of the statements is true in all bar one possible case.
George did it, and Kumar is telling the truth.
Here's how you can spot it quickly:
George's own statement is true if George didn't do it. Therefore, if George didn't do it, all of the others are lying.
From this, we know that, if George didn't do it, then Sonia didn't do it (Atal is lying), Kumar didn't do it (Sonia is lying), and neither Atal nor Laloo did it (Laloo is lying - as the statement is conditional, it is only a lie if the antecedent (Atal didn't do it) is true and the consequent (Laloo did it) is false)
Therefore, if George is telling the truth, nobody did it.
By process of elimination, we therefore conclude that George did it.
Note that this is consistent, as Atal is lying (Sonia didn't do it), Sonia is lying (Kumar didn't do it), and Laloo is lying (neither Atal nor Laloo did it), and of course George is lying while Kumar is telling the truth.