(9)The amount of deduction to an undertaking which begins commercial production or refining of mineral oil shall be hundred per cent. of the profits for a period of seven consecutive assessment years including the initial assessment year:Provided that where the undertaking is located in North-Eastern Region, it has begun or begins commercial production of mineral oil before the 1st day of April, 1997 and where it is located in any part of India, it begins commercial production of mineral oil on or after the 1st day of April, 1997:Provided that where the undertaking is engaged in refining of mineral oil, it begins refining on or after the 1st day of October, 1998.
