Advance tax shortfall exclusion for under estimated capital gains and specified income when tax is paid by the due instalment. The amendment exempts from section 234C any shortfall in advance tax caused by under estimating or failing to estimate capital gains or the specified income category, provided the assessee pays the full tax attributable to that income as part of the immediately due instalment or, if none is due, by the last day of the financial year. It also replaces the Explanation's reference to tax 'deductible at source' under Chapter XVII B with 'deductible or collectible at source' under Chapter XVII.