(1) The Deputy Commissioners having jurisdiction over the area may, for valid and sufficient reasons, to be recorded in writing, condone delay,-

(a) in the applying for any refund under this Act and Rules made there under,

(b) in filing option under section 8 of this Act, up to 31st December 2008 for the years 2005-06, 2006-07 and 2007-08:

Provided that the time limit for completion of any assessment under this Act shall be extended by a further period of three years from the date of condoning such delay, under this section.