For the purpose of calculation of 5% per quarter from the "date of purchase of goods" to till the date of dipose to be taken.
Date of purchase means
1) whether date of purchase by borrower?
or
2)Date of repossession taken by financiers?
Goods repossession by is not considered as supply
So
Offcourse the date of purchase will be the date on which default borrower purchased.
Note : kindly read the priviso also it clearly mention the date of purchase