Service tax not paid before filling the income tax return

Hi,

As on 31st March -2016 we where suppose to pay Service tax of Rs XXX amount and we havent paid the amount fully, we have paid only the partial amount. There is still a balance amount of service tax has to be paid. 

Eg : as on 31 st March 2016 to be payable- 5,00,000, but paid only 2 ,00,000 till September end, the balance of 3,00,000.00

1. Now what is the treatement for the balance 3,00,000.00 amount which is not paid before filling the income tax return ?

2. Do we need to mention this is the audit report ? 

Do we need to disallow balance payable under Section 43B .

Thanks is Advance !!