(1) Where the holder of a certificate of registration granted under rule 3 desires the certificate to be amended, he shall submit an application in Form I for this purpose to the prescribed authority setting out the particulars in respect, of which he desires such amendment and reasons therefor together with the certifi cate of registration and thereupon the prescribed authority may, if he is satisfied with the reason given, make such amendments as he thinks necessary in the certificate of registration.
(2) Notwithstanding anything contained in sub-rule (1), where consequent upon the amendment of any of the items in column No. 2 or 3 of the Schedule to the Act the classification of persons or the rate of tax payable under the Act or both is or are changed and a new classification of persons or a new rate of Tax or both is or are specified then the classification, of persons or the rate of tax mentioned in the certificates of registration in Form II granted under rule 3 to the holders of such certificates prior to such amendment shall stand changed respectively to the new classification of person or the rate of tax or both so specified in the Schedule with effect from the date of coming into force of such amendment.