Hi,
In case of CST, the tax is non-deuctible and the same is added to material cost as well. But VAT is deductible and its added to a different GL, normally. Non-deductible tax (CST) is posted at the time of GR, but deductible tax (VAT) is posted only at the time of invoice. Standard system does not generate any tax postings during GR - Refer the note: 518368 - FAQ: Valuation for the purchase order - Question number: 8
So, as of my knowledge, there is no option to reflect the deuctible taxes during GR.
Regards,
AKPT