Product ID
=AND(COUNTIF($B$11:$B$20,B11)=1,LEN(B11)=6)

Pcs
0 "Pcs"

Amount
=E11*D11

Grand Total
=SUM(F11:F20)

Discount
=IF(F21>500000,F21*9%,IF(F21>300000,F21*3%,IF(F21<500000,F21*1%)))

VAT
=F21*3%

Payable Amount
=F21+F23-F22

Table-2
Quantity/Rate/Amount
=INDEX($D$11:$D$20,MATCH(C30,$C$11:$C$20,0))