Section 8(2)(d) in Goa Value Added Tax Rules, 2005
(d)Where documentary evidence of sales tax charged is available, the value on which the sales tax is calculated shall be used as the basis for claiming the input tax credit and in case such purchases are inclusive of tax that is second sale where tax amount is not separately shown, the value of such stock shall be reduced by ten per cent. and on such reduced stock net of tax shall be determined by applying the following formula: