Section 80(1)(a) in The Tripura University Act, 2006
(a)A dealer effecting sales falling under sub-section (1), sub-section (3) or sub-section (5) of section 5 of the Central Sales Tax Act, 1956, in any tax period shall be eligible for refund of tax, if the input tax credit exceeds the amount of tax payable subject to condition that the exports have been made outside the territory of India. The excess of tax shall be refunded within a period of ninety days on a claim made on a return prescribed to the authority prescribed subject to the provisions of the Act and the rules made thereunder.