Certificate of registration— If the [Chief Commissioner or Commissioner] is satisfied that the applicant fulfils the requirements of clause (v) or clause (vi) [or clause (via)] or clause (vii) of sub-section (2) of section 288 and has been practising before income-tax authorities for not less than one year on the date of the application, the [Chief Commissioner or Commissioner] shall enter the name of the applicant in the register and issue him a certificate of registration in Form No. 40.