Dear Vishal,
As you said the related invoice are in Dispute.
a) If any petition has been filed in the court by the Plantiff (the co. from whom such Invoice Received) then you should talk to the expert i.e Lawyer who is defending this case , evidenve related to these transaction , & after evaluating, if you find that the probability for paying that claims is more likely than not ( more than 50 Percent) then Provision should be made in the A/cs. (As per AS 29)
b) If the same is in Dispute then give the facts regarding those transaction in notes to the Financial Statemtent.