law: 20. In section 49 of the principal Act,
  (a) in sub-section (2), for the word and figures "section 41", the words, figures and letter "section 41 or section 43A" shall be substituted;
  (b) in sub-section (5),
  (i) in clause (c), the following proviso shall be inserted, namely:
  "Provided that the input tax credit on account of State tax shall be utilised towards payment of integrated tax only where the balance of the input tax credit on account of central tax is not available for payment of integrated tax;";
  (ii) in clause (d), the following proviso shall be inserted, namely:
  "Provided that the input tax credit on account of Union territory tax shall be utilised towards payment of integrated tax only where the balance of the input tax credit on account of central tax is not available for payment of integrated tax;".