Rule 12 (7) of the Central Sales Tax Registration and Turnover Rules, 1957, the declaration in Form C or Form F or the Certification in Form E-I or Form E-II shall be furnished to the prescribed authority within three months after the end of the period to which the declaration or the certificate relates:
Provided that if the prescribed authority is satisfied that the person concerned was prevented by sufficient cause from furnishing such declaration or certificate within the aforesaid time, that authority may allow such declaration or certificate to be furnished within such further time as that authority may permit.